Permanent magnet synchronous motor torque control method and device, storage medium and electronic equipment

Abstract

The embodiment of the disclosure provides a kind of permanent magnet synchronous motor torque control method, device, storage medium and electronic equipment, wherein, method includes: obtaining the desired torque of permanent magnet synchronous motor, feedback torque and desired excitation current;According to the desired torque, obtain first torque instruction current;According to the difference of the desired torque and the feedback torque, obtain second torque instruction current;According to the first torque instruction current and the second torque instruction current, obtain third torque instruction current;According to the third torque instruction current and the desired excitation current control the torque of the permanent magnet synchronous motor, in turn, the quick response of torque feedforward control and the robustness characteristics of torque feedback control are ingeniously combined, the anti-interference performance of torque control is improved, the overshoot and pulsation of permanent magnet synchronous machine torque are reduced, and the steady-state deviation of step response is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of motors, and in particular to a torque control method, apparatus, storage medium, and electronic device for a permanent magnet synchronous motor. Background Technology

[0002] Permanent magnet synchronous motors are widely used in industrial and domestic electromechanical equipment such as electric vehicles, trams, elevators, air conditioners, and pumps due to their advantages such as high efficiency, high power density, and fast dynamic characteristics.

[0003] For permanent magnet synchronous motors (PMSMs), common control modes include position control, speed control, and torque control. Torque control can serve as an inner loop for position and speed control, and its performance directly affects the performance of position and speed control. Currently, there are two main torque control methods for PMSMs: direct torque control (DTC) and field-oriented control (FOC). FOC is characterized by separate control of the air gap magnetic field and torque. A typical control design considers obtaining the corresponding current from the desired torque when the magnetic flux is constant, and then controlling the torque by controlling the current.

[0004] However, in the process of realizing this invention, the inventors discovered that the feasibility of such a constant relationship between torque and corresponding current is easily affected by a variety of practical factors, which can easily produce unacceptable accuracy deviations in torque control, thus making the torque control of the permanent magnet synchronous motor inaccurate. Summary of the Invention

[0005] To overcome the problems existing in related technologies, this disclosure provides a torque control method, device, storage medium and electronic equipment for permanent magnet synchronous motors, which can improve the anti-interference performance of torque control and improve the accuracy of torque control.

[0006] According to a first aspect of the present disclosure, a torque control method for a permanent magnet synchronous motor is provided, comprising the following steps:

[0007] Obtain the desired torque, feedback torque, and desired excitation current of the permanent magnet synchronous motor;

[0008] Based on the desired torque, a first torque command current is obtained; based on the difference between the desired torque and the feedback torque, a second torque command current is obtained.

[0009] The third torque command current is obtained based on the first torque command current and the second torque command current;

[0010] The torque of the permanent magnet synchronous motor is controlled according to the third torque command current and the desired excitation current.

[0011] In one embodiment, the step of obtaining a first torque command current based on the desired torque, and obtaining a second torque command current based on the difference between the desired torque and the feedback torque, includes:

[0012] The desired torque is input to the torque feedforward controller, so that the torque feedforward controller outputs the first torque command current based on the gain coefficient of the torque feedforward controller, the flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor, and the desired torque; wherein, when the desired torque remains unchanged, the first torque command current is linearly related to the gain coefficient of the torque feedforward controller.

[0013] The difference between the desired torque and the feedback torque is input to the torque feedback controller, so that the torque feedback controller outputs the second torque command current based on the proportional coefficient, the integral coefficient, and the difference between the desired torque and the feedback torque. The proportional coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor, the torque closed-loop response time parameter, and the excitation current closed-loop control time parameter. The integral coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet synchronous motor, the number of pole pairs, and the torque closed-loop response time parameter.

[0014] This embodiment of the invention improves the anti-interference performance of torque control by combining the fast response of the feedforward control method corresponding to the feedforward controller with the robustness of the feedback control method corresponding to the feedback controller for torque control of the permanent magnet synchronous motor.

[0015] In one embodiment, the step of obtaining a third torque command current based on the first torque command current and the second torque command current includes: taking the sum of the first torque command current and the second torque command current as the third torque command current.

[0016] In one embodiment, the torque control method for a permanent magnet synchronous motor further includes the following steps:

[0017] The gain coefficient of the torque feedforward controller can be adjusted to allow the torque feedforward controller to independently control the torque of the permanent magnet synchronous motor, the torque feedback controller to independently control the torque of the permanent magnet synchronous motor, the torque feedforward controller and the torque feedback controller to control the torque of the permanent magnet synchronous motor in parallel, or the torque control closed-loop time can be adjusted to quickly switch between the torque feedforward controller and the torque feedback controller as needed. Moreover, the torque control closed-loop time constant can be continuously adjusted without changing the gain of the torque feedback controller.

[0018] In one embodiment, the step of controlling the torque of the permanent magnet synchronous motor according to the third torque command current and the desired excitation current includes:

[0019] Based on the desired excitation current and the preset linear compensation method, the third torque command current is linearly compensated to obtain the desired torque current of the permanent magnet synchronous motor.

[0020] The permanent magnet synchronous motor is controlled to operate according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

[0021] In one embodiment, the desired torque current is obtained based on the desired excitation current, the direct-axis winding inductance of the permanent magnet synchronous motor, the quadrature-axis winding inductance of the permanent magnet synchronous motor, and the third torque command current; wherein, when the desired excitation current remains constant, the desired torque current and the third torque command current are linearly related, so that after the desired torque current and the desired excitation current are input to the permanent magnet synchronous motor, the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current.

[0022] In one embodiment, the step of controlling the operation of the permanent magnet synchronous motor according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor varies with the change of the third torque command current, includes:

[0023] Based on the offset difference between the feedback excitation current and the desired excitation current, and the offset difference between the feedback torque current and the desired torque current, the permanent magnet synchronous motor is controlled to operate, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

[0024] According to the embodiments of this disclosure, the permanent magnet synchronous motor is controlled to operate based on the offset difference between the feedback excitation current and the desired excitation current, as well as the offset difference between the feedback torque current and the desired torque current. This allows the motor to obtain a torque that changes with the third torque command current, while the feedback excitation current and the feedback torque current follow the changes in the desired torque current.

[0025] A second aspect of this disclosure provides a torque control device for a permanent magnet synchronous motor, comprising:

[0026] The data acquisition module is used to acquire the desired torque, feedback torque, and desired excitation current of the permanent magnet synchronous motor.

[0027] The first current acquisition module is used to obtain a first torque command current based on the expected torque, and to obtain a second torque command current based on the difference between the expected torque and the feedback torque.

[0028] The second current acquisition module is used to obtain the third torque command current based on the first torque command current and the second torque command current;

[0029] A torque control module is used to control the torque of the permanent magnet synchronous motor according to the third torque command current and the desired excitation current.

[0030] According to a third aspect of the present disclosure, an electronic device is provided, including a processor and a memory; the memory stores a computer program adapted to be loaded by the processor and executed as described above for the torque control method of a permanent magnet synchronous motor.

[0031] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the torque control method for a permanent magnet synchronous motor as described above.

[0032] This embodiment of the disclosure obtains the desired torque, feedback torque, and desired excitation current of a permanent magnet synchronous motor (PMSM); obtains a first torque command current based on the desired torque; obtains a second torque command current based on the difference between the desired torque and the feedback torque; obtains a third torque command current based on the first torque command current and the second torque command current; and controls the torque of the PMSM based on the third torque command current and the desired excitation current. That is, it combines the fast response of the feedforward control method using the first torque command current determined by the desired torque, and the robustness of the feedback control method using the second torque command current determined by the difference between the desired torque and the feedback torque, to perform torque control on the PMSM. This improves the anti-interference performance of torque control, reduces torque overshoot and pulsation in the PMSM, and lowers the steady-state deviation of the step response.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0034] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram illustrating the connection principle of a permanent magnet synchronous motor and a three-phase inverter bridge circuit in one embodiment of the present disclosure.

[0037] Figure 2 This is a flowchart illustrating a torque control method for a permanent magnet synchronous motor in one embodiment of the present disclosure;

[0038] Figure 3 This is a flowchart illustrating a method for obtaining a first torque command current and a second torque command current in one embodiment of the present disclosure;

[0039] Figure 4 This is a schematic diagram illustrating the principle of controlling the torque of a permanent magnet synchronous motor according to an embodiment of this disclosure;

[0040] Figure 5 This is a schematic diagram illustrating linear compensation of the third torque command current according to one embodiment of the present disclosure;

[0041] Figure 6This is a schematic diagram illustrating the torque of a permanent magnet synchronous motor when the excitation current and torque current are controlled in a closed loop, according to one embodiment of this disclosure.

[0042] Figure 7 This is a schematic diagram illustrating the desired torque and the actual output torque of a permanent magnet synchronous motor according to one embodiment of this disclosure;

[0043] Figure 8 for Figure 7 Simplified schematic diagram of the expected torque and the actual output torque of the permanent magnet synchronous motor;

[0044] Figure 9 This is a schematic block diagram illustrating a torque control system for a permanent magnet synchronous motor according to an embodiment of this disclosure;

[0045] Figure 10 This is a schematic block diagram illustrating a torque control device for a permanent magnet synchronous motor according to one embodiment of the present disclosure;

[0046] Figure 11 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0048] It should be understood that the described embodiments are merely some, not all, of the embodiments disclosed herein. All other embodiments obtained by those skilled in the art based on the embodiments disclosed herein without creative effort are within the scope of protection of this disclosure.

[0049] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in the various drawings represent the same or similar elements. In the description of this disclosure, it should be understood that the terms “first,” “second,” “third,” etc., are used only to distinguish similar objects and are not necessarily used to describe a particular order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art will understand the specific meaning of the above terms in this disclosure according to the specific circumstances. The singular forms “a,” “the,” and “the” used in this disclosure and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. The word “if” / “suppose” as used herein can be interpreted as “when,” “when,” or “in response to determination.”

[0050] Furthermore, in the description of this disclosure, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0051] The application environment of the permanent magnet synchronous motor torque control method of this disclosure includes a permanent magnet synchronous motor torque control device. The permanent magnet synchronous motor torque control device can implement the permanent magnet synchronous motor torque method of this disclosure in pure software, or it can implement the permanent magnet synchronous motor torque method of this disclosure in a combination of software and hardware. Taking software implementation as an example, the permanent magnet synchronous motor torque control device is formed by a processor that processes the file to read the corresponding computer program instructions from the non-volatile memory into memory and run them. From a hardware perspective, the permanent magnet synchronous motor torque device can be implemented using at least one hardware form selected from digital signal processing, field-programmable gate arrays, and programmable logic arrays. In one embodiment, the permanent magnet synchronous motor torque control device can also be the permanent magnet synchronous motor itself.

[0052] To facilitate understanding of the design scheme disclosed herein, a brief introduction to the relevant content of the permanent magnet synchronous motor is provided below.

[0053] A permanent magnet synchronous motor is an electric motor that uses permanent magnets for excitation. It mainly consists of a stator, rotor, and end covers. The stator is made of laminated laminations to reduce iron losses during operation, and it houses three-phase AC windings. The rotor can be solid or made of laminated laminations, and it contains permanent magnets.

[0054] Based on the difference in direct and quadrature axis inductance, permanent magnet synchronous motors can be divided into two types: salient-pole and non-salient-pole motors. In non-salient-pole permanent magnet synchronous motors, the direct-axis winding inductance and quadrature axis winding inductance are equal, while in salient-pole permanent magnet synchronous motors, the direct-axis winding inductance and quadrature axis winding inductance are not equal. The permanent magnet synchronous motor in this embodiment is a salient-pole permanent magnet synchronous motor.

[0055] Please see Figure 1 This is a schematic diagram illustrating the connection principle between a permanent magnet synchronous motor and a three-phase inverter bridge circuit in one embodiment. Figure 1As shown, generally, the three-phase AC windings of the permanent magnet synchronous motor 120 are connected to the three-phase inverter bridge circuit 110, which acts as a driver to drive the permanent magnet synchronous motor. The three-phase inverter bridge circuit includes three arms: diodes D1, D2, Q1, and Q2 form the first arm, used to control the output U-phase voltage; diodes D3, D4, Q3, and Q4 form the second arm, used to control the output V-phase voltage; and diodes D5, D6, Q5, and Q6 form the third arm, used to control the output W-phase voltage. The three-phase inverter bridge circuit regulates the three-phase voltage input to the permanent magnet synchronous motor by controlling the switching on and off of transistors Q1, Q2, Q3, Q4, Q5, and Q6, thereby controlling the three-phase current of the permanent magnet synchronous motor and ultimately controlling the torque of the permanent magnet synchronous motor.

[0056] For permanent magnet synchronous motors, torque control is usually achieved by rotating vector control. The characteristic of rotating vector control is that the air gap magnetic field and torque of the motor are controlled separately. A typical control design considers that when the magnetic flux is constant, the current is obtained from the required torque, and then the torque is controlled by controlling the current.

[0057] However, in the process of realizing this invention, the inventors discovered that the feasibility of such a constant relationship between torque and corresponding current is easily affected by a variety of practical factors, which can easily produce unacceptable accuracy deviations in torque control, thus making the torque control of the permanent magnet synchronous motor inaccurate.

[0058] Therefore, embodiments of this disclosure provide a torque control method, apparatus, storage medium, and electronic device for permanent magnet synchronous motors.

[0059] Example 1

[0060] The following will be combined with the appendix Figures 2 to 9 This paper provides a detailed description of the torque control method for permanent magnet synchronous motors provided in the embodiments of this disclosure.

[0061] Please see Figure 2 The torque control method for a permanent magnet synchronous motor provided in this disclosure includes the following steps:

[0062] Step S101: Obtain the desired torque, feedback torque, and desired excitation current of the permanent magnet synchronous motor.

[0063] The desired torque is the torque required to be output by the permanent magnet synchronous motor, which can be a reference torque curve. The desired excitation current is the excitation current required to be output by the permanent magnet synchronous motor.

[0064] The feedback torque is the real-time torque obtained by detecting the permanent magnet synchronous motor. Without considering noise, the detected feedback torque is the actual torque of the permanent magnet synchronous motor.

[0065] Since direct measurement of torque is difficult, and torque satisfies the following relationship with excitation current and torque current:

[0066] T = kN p {ψ+(L d -L q )i sd}i sq

[0067] Therefore, the feedback torque can also be derived from the feedback excitation current and the feedback torque current. Specifically, the feedback torque is:

[0068] T fbk =kN p {ψ+(L d -L q )i sd_fbk}i sq_fbk

[0069] Among them, T fbk For feedback torque; i sd_fbk For feedback excitation current; i sq_fbk For feedback torque current; k is the transformation coefficient, which is a constant; N p L is the number of pole pairs; ψ is the magnetic flux of the permanent magnet; L d L q Let dq represent the direct-axis winding inductance and quadrature-axis winding inductance of a permanent magnet synchronous motor in a two-phase quadrature-direct-axis coordinate system.

[0070] Among them, the feedback excitation current is the real-time excitation current obtained by detecting the permanent magnet synchronous motor, and the feedback torque current is the real-time excitation current obtained by detecting the permanent magnet synchronous motor. Without considering noise, the detected feedback excitation current is the actual excitation current of the permanent magnet synchronous motor; the feedback torque current is the actual torque current of the permanent magnet synchronous motor.

[0071] The excitation current and torque current satisfy the following relationship with the three-phase current:

[0072]

[0073] In the above formula, i su i sv and i sw For three-phase current; K is the transformation coefficient, which is used when performing an absolute coordinate transformation with invariant energy. When performing a relative transformation in which the amplitude remains unchanged before and after the transformation isd i sq For the excitation current and torque current in the two-phase DC components; θ r The synchronous rotation angle of the rotor can be calculated by multiplying the mechanical rotation angle calculated by the encoder by the number of magnetic pole pairs Np; or it can be estimated by the Hall sensor.

[0074] Therefore, the three-phase current of the permanent magnet synchronous motor can be measured to obtain the three-phase feedback current. Then, the three-phase feedback current can be transformed using the above formula to obtain the feedback excitation current and the feedback torque current.

[0075] When measuring the three-phase current of a permanent magnet synchronous motor, due to the symmetry of the current, the current of the last phase can be obtained by measuring any two phases of the current. For example, if the actual measurement involves the currents of phases u and v, i... su i sv w phase current i sw For: i sw =-(i su +i sv When measuring current, it can be done using a current sensor or by connecting a shunt resistor, also known as a shunt resistor, in series with the three-phase windings of the permanent magnet synchronous motor. This disclosure does not limit the measurement.

[0076] Step S102: Obtain the first torque command current based on the desired torque; obtain the second torque command current based on the difference between the desired torque and the feedback torque.

[0077] In one embodiment, see Figure 3 Step S102, which involves obtaining a first torque command current based on the desired torque and a second torque command current based on the difference between the desired torque and the feedback torque, includes:

[0078] Step S1021: Input the desired torque to the torque feedforward controller so that the torque feedforward controller outputs a first torque command current based on the gain coefficient of the torque feedforward controller, the flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor and the desired torque; wherein, when the desired torque is constant, the first torque command current is linearly related to the gain coefficient of the torque feedforward controller.

[0079] The first torque command current is the current to be applied directly based on the desired torque obtained by the torque feedforward controller using the mathematical model of motor torque control. The torque feedforward controller has the characteristic of fast response. However, when the parameters of the motor torque mathematical model are inaccurate or there are external disturbances, the torque feedforward controller cannot adjust automatically and has poor robustness.

[0080] Specifically, the first torque command current is:

[0081]

[0082] Among them, i1′ sq_ref K is the first torque command current; FF N is the gain coefficient of the torque feedforward controller; p ψ is the number of pole pairs in the permanent magnet synchronous motor; T is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor; ref This represents the desired torque.

[0083] Step S1022: Input the difference between the desired torque and the feedback torque to the torque feedback controller, so that the torque feedback controller outputs a second torque command current based on the proportional coefficient, the integral coefficient, and the difference between the desired torque and the feedback torque; wherein, the proportional coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor, the torque closed-loop response time parameter, and the excitation current closed-loop control time parameter; the integral coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs, and the torque closed-loop response time parameter.

[0084] The second torque command current is the current that the torque feedback controller outputs based on the difference between the desired torque and the feedback torque, so that the torque of the permanent magnet synchronous motor follows the change of the reference torque.

[0085] Specifically, the second torque command current is:

[0086]

[0087]

[0088] Among them, i2′ sq_ref For the second torque command current; K P_T K is the proportional gain of the torque feedback controller; I_T T represents the integral coefficient of the torque feedback controller. ref T is the expectation matrix; fbk is the feedback matrix; s is the Laplace coefficient; N p ψ is the number of pole pairs in the permanent magnet synchronous motor; T is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor; isq_cl T is the time parameter for the closed-loop control of the excitation current; cl The set torque closed-loop response time parameter.

[0089] It should be noted that when implementing the permanent magnet synchronous motor torque control method of this disclosure, the feedforward controller and torque feedback controller need to be designed based on the motor torque control mathematical model. To better understand the design scheme of this disclosure, the motor torque control mathematical model used in one embodiment of this disclosure is described in detail below.

[0090] Depend on Figure 1 As shown, a permanent magnet synchronous motor has three coordinate systems: a three-phase coordinate system uvw, a two-phase coordinate system αβ, and a two-phase perpendicular axis coordinate system dq that is stationary relative to the rotor.

[0091] The DC component in the two-phase perpendicular coordinate system dq is represented as: excitation current i sd and torque current i sd The torque T and torque current component i of a permanent magnet synchronous motor sq With equivalent magnetic flux ψ eq The relational expression satisfies the following relationship:

[0092] T∝ψ eq i sq Equation 1

[0093] Specifically, for a salient-pole permanent magnet synchronous motor, the torque T and torque current i of the permanent magnet synchronous motor are related. sq With equivalent magnetic flux ψ eq The following relationship must be satisfied:

[0094] T = kN p {ψ+(L d -L q )i sd}i sq Equation 2

[0095] Among them, L d L q Let dq represent the direct-axis and quadrature-axis winding inductance values ​​of the permanent magnet synchronous motor in a two-phase quadrature-direct-axis coordinate system; k is the transformation coefficient, which is a constant; N p ψ is the number of pole pairs in the permanent magnet synchronous motor; ψ is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor.

[0096] From the above equation, it can be seen that the output impedance torque T r Partially related to the excitation current i sd and torque current i sq The product i sd i sq It is directly proportional to the torque T of the permanent magnet synchronous motor, that is, the torque T of the permanent magnet synchronous motor is directly proportional to the excitation current i. sd and torque current i sq All of these are non-linear relationships.

[0097] In the process of realizing this disclosure, the inventors discovered that: by comparing equations 1 and 2, it can be seen that...

[0098] ψ eq =N p {ψ+(L d -L q )i sd Equation 3

[0099] Equation 2 can then be transformed into Equation 4.

[0100] T = kN p ψi sq +kN p (L d -L q )i sd i sq Equation 4

[0101] As shown in Equation 4, the torque T of a salient-pole permanent magnet synchronous motor is determined by the electromagnetic torque To. m and impedance torque T r It consists of two parts, as shown in Equations 5 and 6.

[0102] T m =kN p ψi sq Equation 5

[0103] T r =kN p (L d -L q )i sd i sq Equation 6

[0104] In the process of realizing this disclosure, the inventors further discovered that, according to equations 4 to 6, the following can be obtained: Figure 3 The upper part of the diagram shows the torque principle of the permanent magnet synchronous motor.

[0105] As Figure 4 As shown, 211 is the impedance torque calculation unit, used to calculate the impedance torque according to Equation 6; 213 is the electromagnetic torque calculation unit, used to calculate the electromagnetic torque according to Equation 5; 212 is the torque summation unit, used to sum the impedance torque and electromagnetic torque to obtain the torque of the permanent magnet synchronous motor. For example... Figure 4 The torque output block diagram shown in the upper part of the figure can be equivalently transformed to obtain the following: Figure 4 The lower part of the diagram shows the torque deformation principle of a permanent magnet synchronous motor. 214 is a torque calculation unit used to calculate the torque based on the excitation current i. sd and torque current isq Calculate the torque T.

[0106] In the process of realizing this disclosure, the inventors further discovered that the excitation current i can be eliminated by adding linear compensation. sd The impact on the torque output of a permanent magnet synchronous motor, specifically, such as Figure 5 As shown, a torque linear compensation unit 215 is added before the torque calculation unit 214. The following linear compensation formula can be obtained from the torque linear compensation unit 215:

[0107]

[0108] Transforming equation 7 yields compensation equation 8.

[0109]

[0110] Substituting equation 8 into equation 4 yields the torque calculation formula for equation 9.

[0111] T = kN p ψi′ sq Equation 9

[0112] As can be seen from Equation 9, within a permanent magnet synchronous motor, the torque T of the permanent magnet synchronous motor is actually determined only by i′ sq To determine, that is, to remove the excitation current i sd The effect on torque output, where i′ sq This is the torque command current.

[0113] In practical torque control processes, direct-axis current controllers and quadrature-axis current controllers are generally used to perform PI closed-loop control on the excitation current and torque current. If the time constants of the excitation current closed-loop and the torque current closed-loop are set to T... isd_cl and T isq_cl Then the overall transfer function of the current-controlled closed loop can be expressed as Equations 10 and 11. For example... Figure 6 As shown, 311 is the closed-loop transfer function unit of the direct-axis current controller; 313 is the closed-loop transfer function unit of the torque controller; and 312 is the excitation current feedforward calculation unit. Figure 6 As shown, we can obtain

[0114]

[0115]

[0116] In practical controller design, the following linearized compensation equations 12 and 13 can be used to replace equation 8 to decouple the excitation current, thereby eliminating the influence of the excitation current on the torque of the permanent magnet synchronous motor.

[0117]

[0118]

[0119] In the above formula, to distinguish it from Equation 8 and to facilitate understanding of the design scheme of this disclosure, i is used. sq_ref i′ represents the desired torque current of the permanent magnet synchronous motor. sq_ref Indicates torque command current; i sd_ff To the time constant T of the excitation closed-loop current isd_cl The same excitation command current output by the feedforward controller; i sd_ref denoted as the desired excitation current of the permanent magnet synchronous motor; s is the Laplace operator.

[0120] Substituting equations 10 through 13 into equation 4 yields equation 14. From this equation, it can be seen that current i′ can pass through. sq_ref Linearize the torque output.

[0121]

[0122] When k = 1.5, we can obtain:

[0123]

[0124] In other words, Equation 15 is a mathematical model for motor torque control according to an embodiment of this disclosure. The torque in this mathematical model can be decoupled from the desired excitation current. Specifically, the torque in the mathematical model is obtained based on the number of pole pairs of the permanent magnet synchronous motor, the flux of the permanent magnets, the torque command current, and the torque closed-loop current time constant. The torque of the permanent magnet synchronous motor has a linear relationship with the torque command current, making the torque of the permanent magnet synchronous motor change linearly with the change in the torque command current, thus facilitating the design of the torque controller.

[0125] Therefore, torque feedforward controllers and torque feedback controllers can be designed based on the above-mentioned mathematical model of motor torque control.

[0126] Specifically, according to Equation 15, we can obtain:

[0127]

[0128] Based on Equation 16, add a gain coefficient K. FF ,available:

[0129]

[0130] Therefore, the torque feedforward controller directly outputs the first torque command current based on the input desired torque, as well as the gain coefficient of the torque feedforward controller stored inside the torque feedforward controller, the magnetic flux of the permanent magnet of the permanent magnet synchronous motor, and the number of pole pairs of the permanent magnet synchronous motor.

[0131] The torque feedback controller using PI control obtains the proportional coefficient and integral coefficient of the torque feedback controller according to the internal model method. Then, the torque feedback controller outputs a second torque command current based on the difference between the input desired torque and the feedback torque, as well as the proportional coefficient and integral coefficient of the torque feedback controller stored internally.

[0132] Step S103: Obtain the third torque command current based on the first torque command current and the second torque command current.

[0133] Optionally, the step of obtaining the third torque command current based on the first torque command current and the second torque command current includes: using the sum of the first torque command current and the second torque command current as the third torque command current, so as to control the torque of the permanent magnet synchronous motor in combination with the first torque command current and the second torque command current. Specifically, the third torque command current is:

[0134] i′ sq_ref =i1′ sq_ref +i2′ sq_ref Equation 18

[0135] i′ sq_ref i1′ is the third torque command current. sq_ref i2′ is the first torque command current. sq_ref This is the second torque command current.

[0136] Step S104: Control the torque of the permanent magnet synchronous motor according to the third torque command current and the desired excitation current.

[0137] This embodiment of the present disclosure obtains the desired torque, feedback torque, and desired excitation current of a permanent magnet synchronous motor (PMSM); obtains a first torque command current based on the desired torque; obtains a second torque command current based on the difference between the desired torque and the feedback torque; obtains a third torque command current based on the first and second torque command currents; and controls the torque of the PMSM based on the third torque command current and the desired excitation current. That is, it combines the fast response of the feedforward control method using the first torque command current determined by the desired torque with the robustness of the feedback control method using the second torque command current determined by the difference between the desired torque and the feedback torque to perform torque control on the PMSM, thereby improving the anti-interference performance of torque control, reducing torque overshoot and pulsation of the PMSM, and lowering the steady-state deviation of the step response.

[0138] In one embodiment, step S104, which involves controlling the torque of the permanent magnet synchronous motor based on the third torque command current and the desired excitation current, includes:

[0139] Step S1041: Based on the desired excitation current and the preset linear compensation method, perform linear compensation on the third torque command current to obtain the desired torque current of the permanent magnet synchronous motor.

[0140] In one embodiment, the desired torque current is obtained based on the desired excitation current, the direct-axis winding inductance of the permanent magnet synchronous motor, the quadrature-axis winding inductance of the permanent magnet synchronous motor, and the torque command current; wherein, when the desired excitation current remains constant, the desired torque current and the torque command current have a linear relationship. Specifically, the desired torque current of the permanent magnet synchronous motor is:

[0141]

[0142] In the above formula, i sq_sef i represents the desired torque current; sq_ref L represents the desired torque current. d L q Here, N represents the direct-axis winding inductance and quadrature-axis winding inductance of the permanent magnet synchronous motor; k is the transformation coefficient, which is a constant; N... p ψ is the number of pole pairs in the permanent magnet synchronous motor; ψ is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor.

[0143] Step S1042: Control the operation of the permanent magnet synchronous motor according to the desired excitation current and desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

[0144] The torque of a permanent magnet synchronous motor (PMSM) is obtained from the number of pole pairs, the magnetic flux of the permanent magnets, and the torque command current. The torque and torque command current have a linear relationship, ensuring that the torque changes linearly with the torque command current. Specifically, the torque is:

[0145] T = kN p ψi′ sq

[0146] In the above formula, T is the torque of the permanent magnet synchronous motor; k is the transformation coefficient, which is a constant; N p ψ is the number of pole pairs in the permanent magnet synchronous motor; ψ is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor; i′ sq This is the torque command current.

[0147] In one embodiment, step S1043, which controls the operation of the permanent magnet synchronous motor based on the desired excitation current and the desired torque current to decouple the torque of the permanent magnet synchronous motor from the desired excitation current, includes: controlling the operation of the permanent magnet synchronous motor based on the offset difference between the feedback excitation current and the desired excitation current and the offset difference between the feedback torque current and the desired torque current, so as to decouple the torque of the permanent magnet synchronous motor from the desired excitation current, and to make the torque of the permanent magnet synchronous motor change with the change of the third torque command current.

[0148] Specifically, the offset difference between the feedback excitation current and the desired excitation current is input to the direct-axis current controller for PI regulation to output an excitation voltage output command. The offset difference between the feedback torque current and the desired torque current is input to the quadrature-axis current controller for PI regulation to output a torque voltage output command. Then, the permanent magnet synchronous motor is controlled to operate according to the excitation voltage output command and the torque voltage output command, so as to decouple the torque of the permanent magnet synchronous motor from the desired excitation current.

[0149] The proportional and integral coefficients of the direct-axis current controller, as well as the proportional and integral coefficients of the quadrature-axis current controller, are set based on the motor torque control model and the internal model control method, as detailed below:

[0150]

[0151]

[0152] In the above formula, K P_sd K is the proportional coefficient of the direct-axis current controller. I_sd K represents the integral coefficient of the direct-axis current controller. P_sq K is the proportional coefficient of the quadrature-axis current controller. I_sd R is the integral coefficient of the quadrature-axis current controller; s For the stator winding of a permanent magnet synchronous motor; L d L q r is the inductance of the stator coil in the dq coordinate system. sd_cl T sq_cl These represent the closed-loop current-time parameter of the excitation current and the closed-loop current parameter of the torque current, respectively. These two parameters can be set by the user within a certain range according to the specific system response speed requirements.

[0153] At this point, the output torque of the permanent magnet synchronous motor can be obtained from the desired torque using the following method: Figure 7 The control block diagram shown is used to represent the control block diagram, and then... Substitute Figure 7 After simplification, we can obtain the following: Figure 8The transmission model from the desired torque to the output torque of the permanent magnet synchronous motor, as shown, can be expressed as follows:

[0154]

[0155] As shown in Equation 18, by adjusting the gain coefficient of the torque feedforward controller, the torque can be controlled independently by the torque feedforward controller, independently by the torque feedback controller, or in parallel by both the torque feedforward and torque feedback controllers. Alternatively, the torque control closed-loop time can be adjusted to customize the response time according to actual needs, thereby improving control performance and adaptability. Specifically:

[0156] (1) Coefficient k FF When = 0, the closed-loop time constant for controlling the permanent magnet synchronous motor is only the torque closed-loop time constant T. cl At this point, the feedback torque controller independently controls the torque of the permanent magnet synchronous motor.

[0157] (2) When the coefficient At that time, the closed-loop time constant for controlling the permanent magnet synchronous motor is only when the closed-loop time constant is T. isq_cl The closed-loop time constant of the q-axis current controller is consistent, and at this time the feedforward controller independently controls the torque of the permanent magnet synchronous motor.

[0158] (3) When the coefficient When the time constant changes over time, the time constant is in T cl With T isq_cl The variation occurs between intervals. That is, by adjusting the gain coefficient k of the feedforward controller. FF The value, within the range Internal variations, without changing the gain of the torque feedback controller, can adjust the torque control closed-loop time constant within T. cl With T isq_cl Continuous adjustment between them.

[0159] The following is a specific example to illustrate the design scheme disclosed herein:

[0160] like Figure 9 As shown, this is a torque control system for a permanent magnet synchronous motor in one embodiment. The torque control system includes a power modulation unit 411, a permanent magnet synchronous motor 412, a rotor position and speed estimation unit 413, a current sensing and coordinate transformation unit 414, a low-pass filter 415, a torque estimation unit 416, a torque feedforward controller 417, a torque feedback controller 418, a torque command current fusion unit 419, a linear compensation unit 420, a current controller unit 421, and a two-phase to three-phase current conversion unit 422.

[0161] The power modulation unit 411 provides power to the permanent magnet synchronous motor 412. The power modulation unit 411 modulates a sinusoidal voltage signal by rapidly switching the power switching transistors via a controller signal, which is then applied to the permanent magnet synchronous motor. This allows the permanent magnet synchronous motor 412 to output a continuously varying, small-pulsation, and fast-responding torque. The power modulation unit 411 may include a three-phase inverter bridge circuit. The three-phase AC windings of the permanent magnet synchronous motor 412 are connected to the three-phase inverter bridge circuit, which acts as a driver to operate the permanent magnet synchronous motor.

[0162] The rotor position and speed estimation unit 413 uses pulse signals from an encoder or Hall effect device as input and leverages the microcontroller's rapid processing to estimate the absolute position (i.e., the direction angle of the magnetic field) and speed of the motor rotor in real time. This rotation angle information is used for coordinate transformation in vector control, and the speed information is also used as input to the non-interference decoupling module.

[0163] The current acquisition and coordinate transformation unit 414 uses a current sensor to detect the current signal, which is then appropriately amplified by a signal conditioning circuit before being sampled by a digital-to-analog converter chip and used as a current closed-loop control signal. When measuring the three-phase current of a permanent magnet synchronous motor, based on the symmetry of the current, the current of the last phase can be obtained by measuring any two phases. The acquired current signal, represented in the stationary UVW coordinate system, is converted to the two-phase DC component, i.e., the feedback excitation current i, represented in the dq coordinate system that rotates synchronously with the rotor. sd_fbk and feedback torque current i sq_fbk .

[0164] The torque estimation unit 416 estimates the feedback excitation current i after filtering by the low-pass filter 415. sd_fbk and feedback torque current i sq_fbk Calculate the output feedback torque T fbk ; Calculate the feedback torque T fbk The method is as follows: T fbk =kN p {ψ+(L d -L q )i sd_fbk}i sq_fbk ;

[0165] The torque feedback controller 417 adjusts according to the desired torque T. ref Output the first torque command current i1′ sq_ref The calculation formula is as follows:

[0166] The torque feedback controller 418 operates based on the torque deviation value T. err Output the second torque command current i2′ sq_ref The calculation method is as follows:

[0167] The torque command current fusion unit 419, based on the first torque command current i1′ sq_ref Second torque command current i2′ sq_ref Obtain the third torque current i′ sq_ref The calculation method is as follows: i′ sq_ref =i1′ sq_ref +i2′ sq_ref ;

[0168] The linear compensation unit 420 calculates the input desired excitation current i. sq_ref and the third torque command current i′ sq_ref Through a preset linear compensation method, the torque command current i′ is adjusted. sq_ref Linear compensation is performed to obtain the desired torque current i of the permanent magnet synchronous motor. sq_ref The calculation method is as follows:

[0169] The current controller unit 421 consists of a direct-axis current controller, a quadrature-axis current controller, and a non-interference decoupling module. The non-interference decoupling module decouples the direct-axis and quadrature-axis currents; both the direct-axis and quadrature-axis current controllers are PI controllers. The direct-axis current controller operates based on the feedback excitation current i. sd_fbk and the desired excitation current i sd_ref The offset difference is used to output the excitation current control signal. The quadrature axis current controller outputs the excitation current control signal based on the feedback torque current i. sq_fbk and desired torque current i sq_ref The offset difference is used to obtain the torque current control signal.

[0170] The two-phase to three-phase current conversion unit 422 converts the excitation current control signal and the torque current control signal into a three-phase control voltage signal.

[0171] The power modulation unit 411 adjusts the three-phase voltage input to the permanent magnet synchronous motor 412 according to the three-phase control voltage signal.

[0172] The permanent magnet synchronous motor 423 adjusts the three-phase current according to the adjusted three-phase voltage to control the torque output. This allows the permanent magnet synchronous motor to pass through the compensated torque current, decoupling the output torque of the permanent magnet synchronous motor from the target excitation current. This results in a torque that varies with the third torque adjustment current, i.e., a torque that follows the desired torque. Specifically, the relationship between the desired torque and the output torque of the permanent magnet synchronous motor is expressed as follows:

[0173]

[0174] Example 2

[0175] The following are embodiments of the apparatus disclosed herein, which can be used to execute the method described in Embodiment 1 of this disclosure. For details not disclosed in the apparatus embodiments of this disclosure, please refer to the method described in Embodiment 1 of this disclosure.

[0176] Please see Figure 9 The present disclosure discloses a torque control module 200 for a permanent magnet synchronous motor, comprising:

[0177] The data acquisition module 201 is used to acquire the desired torque, feedback torque and desired excitation current of the permanent magnet synchronous motor.

[0178] The first current acquisition module 202 is used to obtain a first torque command current based on the desired torque, and to obtain a second torque command current based on the difference between the desired torque and the feedback torque.

[0179] The second current acquisition module 203 is used to obtain the third torque command current based on the first torque command current and the second torque command current.

[0180] The torque control module 204 is used to control the torque of the permanent magnet synchronous motor according to the third torque command current and the desired excitation current.

[0181] This embodiment of the present disclosure obtains the desired torque, feedback torque, and desired excitation current of a permanent magnet synchronous motor (PMSM); obtains a first torque command current based on the desired torque; obtains a second torque command current based on the difference between the desired torque and the feedback torque; obtains a third torque command current based on the first and second torque command currents; and controls the torque of the PMSM based on the third torque command current and the desired excitation current. That is, it combines the fast response of the feedforward control method using the first torque command current determined by the desired torque with the robustness of the feedback control method using the second torque command current determined by the difference between the desired torque and the feedback torque to perform torque control on the PMSM, thereby improving the anti-interference performance of torque control, reducing torque overshoot and pulsation of the PMSM, and lowering the steady-state deviation of the step response.

[0182] In one embodiment, the first current acquisition module 202 includes:

[0183] The first torque command current acquisition module 2021 is used to input the desired torque to the torque feedforward controller, so that the torque feedforward controller outputs the first torque command current according to the gain coefficient of the torque feedforward controller, the flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor and the desired torque; wherein, when the desired torque is constant, the first torque command current is linearly related to the gain coefficient of the torque feedforward controller.

[0184] The first torque command current is the current to be applied directly based on the desired torque obtained by the torque feedforward controller using the mathematical model of motor torque control. The torque feedforward controller has the characteristic of fast response. However, when the parameters of the motor torque mathematical model are inaccurate or there are external disturbances, the torque feedforward controller cannot adjust automatically and has poor robustness.

[0185] Specifically, the first torque command current is:

[0186]

[0187] Among them, i1′ sq_ref K is the first torque command current; FF N is the gain coefficient of the torque feedforward controller; p ψ is the number of pole pairs in the permanent magnet synchronous motor; T is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor; ref This represents the desired torque.

[0188] The second torque command current module is used to input the difference between the desired torque and the feedback torque to the torque feedback controller, so that the torque feedback controller outputs a second torque command current based on the proportional coefficient, the integral coefficient, and the difference between the desired torque and the feedback torque. The proportional coefficient of the torque feedback controller is obtained based on the flux of the permanent magnet in the permanent magnet synchronous motor, the number of pole pairs in the permanent magnet synchronous motor, the torque closed-loop response time parameter, and the excitation current closed-loop control time parameter. The integral coefficient of the torque feedback controller is obtained based on the flux of the permanent magnet in the permanent magnet synchronous motor, the number of pole pairs, and the torque closed-loop response time parameter.

[0189] In one embodiment, the torque control module 204 includes:

[0190] The desired torque current acquisition module is used to linearly compensate the third torque command current based on the desired excitation current and a preset linear compensation method to obtain the desired torque current of the permanent magnet synchronous motor.

[0191] In one embodiment, the desired torque current is obtained based on the desired excitation current, the direct-axis winding inductance of the permanent magnet synchronous motor, the quadrature-axis winding inductance of the permanent magnet synchronous motor, and the torque command current; wherein, when the desired excitation current remains constant, the desired torque current and the torque command current have a linear relationship. Specifically, the desired torque current of the permanent magnet synchronous motor is:

[0192]

[0193] In the above formula, i sq_ref i represents the desired torque current; sq_ref L represents the desired torque current. d Lq Here, N represents the direct-axis winding inductance and quadrature-axis winding inductance of the permanent magnet synchronous motor; k is the transformation coefficient, which is a constant; N... p ψ is the number of pole pairs in the permanent magnet synchronous motor; ψ is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor.

[0194] The control module is used to control the operation of the permanent magnet synchronous motor according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

[0195] The torque of a permanent magnet synchronous motor (PMSM) is obtained from the number of pole pairs, the magnetic flux of the permanent magnets, and the torque command current. The torque and torque command current have a linear relationship, ensuring that the torque changes linearly with the torque command current. Specifically, the torque is:

[0196] T = kN p ψi′ sq

[0197] In the above formula, T is the torque of the permanent magnet synchronous motor; k is the transformation coefficient, which is a constant; N p ψ is the number of pole pairs in the permanent magnet synchronous motor; ψ is the magnetic flux of the permanent magnet in the permanent magnet synchronous motor; i′ sq This is the torque command current.

[0198] In one embodiment, the control module includes functions for: controlling the operation of a permanent magnet synchronous motor based on the offset difference between the feedback excitation current and the desired excitation current and the offset difference between the feedback torque current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor varies with the change of the third torque command current.

[0199] Specifically, the offset difference between the feedback excitation current and the desired excitation current is input to the direct-axis current controller for PI regulation to output an excitation voltage output command. The offset difference between the feedback torque current and the desired torque current is input to the quadrature-axis current controller for PI regulation to output a torque voltage output command. Then, the permanent magnet synchronous motor is controlled to operate according to the excitation voltage output command and the torque voltage output command, so as to decouple the torque of the permanent magnet synchronous motor from the desired excitation current.

[0200] The proportional and integral coefficients of the direct-axis current controller, as well as the proportional and integral coefficients of the quadrature-axis current controller, are set based on the motor torque control model and the internal model control method, as detailed below:

[0201]

[0202]

[0203] In the above formula, K P_sd K is the proportional coefficient of the direct-axis current controller. I_sd K represents the integral coefficient of the direct-axis current controller. P_sq K is the proportional coefficient of the quadrature-axis current controller. I_sd R is the integral coefficient of the quadrature-axis current controller; s For the stator winding of a permanent magnet synchronous motor; L d L q T represents the inductance of the stator coil in the dq coordinate system. sd_cl T sq_cl These represent the closed-loop current-time parameter of the excitation current and the closed-loop current parameter of the torque current, respectively. These two parameters can be set by the user within a certain range according to the specific system response speed requirements.

[0204] At this point, the output torque of the permanent magnet synchronous motor from the desired torque can be expressed as:

[0205]

[0206] By adjusting the gain coefficient of the torque feedforward controller, the response time can be adjusted according to actual needs, thereby improving control performance and adaptability. Specifically:

[0207] (1) Coefficient k FF When = 0, the closed-loop time constant for controlling the permanent magnet synchronous motor is only the torque closed-loop time constant T. cl At this point, the feedback torque controller independently controls the torque of the permanent magnet synchronous motor.

[0208] (2) When the coefficient At that time, the closed-loop time constant for controlling the permanent magnet synchronous motor is only when the closed-loop time constant is T. isq_cl The closed-loop time constant of the q-axis current controller is consistent, and at this time the feedforward controller independently controls the torque of the permanent magnet synchronous motor.

[0209] (3) When the coefficient When the time constant changes over time, the time constant is in T cl With T isq_cl The variation occurs between intervals. That is, by adjusting the gain coefficient k of the feedforward controller. FF The value, within the range Internal variations, without changing the gain of the torque feedback controller, can adjust the torque control closed-loop time constant within T.cl With T isq_cl Continuous adjustment between them.

[0210] Example 3

[0211] The following are embodiments of the device disclosed herein, which can be used to execute the methods described in Embodiment 1 of this disclosure. For details not disclosed in the embodiments of the device disclosed herein, please refer to the methods described in Embodiment 1 of this disclosure.

[0212] Please see Figure 11 This disclosure also provides an electronic device 300, which may specifically be a computer, mobile phone, tablet computer, interactive flat panel, etc. In an exemplary embodiment of this disclosure, the electronic device 300 is a torque control device for a permanent magnet synchronous motor. The electronic device 300 may include: at least one processor 301, at least one memory 302, at least one display 303, at least one network interface 304, user interface 305, and at least one communication bus 306.

[0213] User interface 305 is primarily used to provide an input interface for users and to acquire user input data. Optionally, user interface 306 may also include a standard wired interface or a wireless interface.

[0214] The network interface 304 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0215] The communication bus 306 is used to enable communication between these components.

[0216] The processor 301 may include one or more processing cores. The processor 310 connects to various parts of the electronic device 300 via various interfaces and lines, and performs various functions and processes data of the electronic device 300 by running or executing instructions, programs, code sets, or instruction sets stored in memory 320, and by calling data stored in memory 302. Optionally, the processor 301 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 301 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 301 and may be implemented as a separate chip.

[0217] The memory 302 may include random access memory (RAM) or read-only memory. Optionally, the memory 302 may include a non-transitory computer-readable storage medium. The memory 302 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 302 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 302 may also be at least one storage device located remotely from the aforementioned processor 301. Figure 11 As shown, the memory 320, which serves as a computer storage medium, may include an operating system, a network communication module, and a user.

[0218] The processor 301 can be used to call the application program of the permanent magnet synchronous motor torque control method stored in the memory 302, and specifically execute the method steps of Embodiment 1 shown above. For the specific execution process, please refer to the detailed description shown in Embodiment 1, which will not be repeated here.

[0219] Example 4

[0220] This disclosure also provides a computer-readable storage medium having a computer program stored thereon, the instructions of which are adapted to be loaded by a processor and executed by the method steps of Embodiment 1 shown above. For details of the execution process, please refer to the specific descriptions shown in the embodiments, which will not be repeated here. The device containing the storage medium can be an electronic device such as a personal computer, laptop computer, smartphone, or tablet computer.

[0221] For the device embodiments, since they basically correspond to the method embodiments, the relevant details can be found in the descriptions of the method embodiments. The device embodiments described above are merely illustrative; components described as separate parts may or may not be physically separate, and components shown as units may or may not be physical units, meaning they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this disclosure according to actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0222] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, systems, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure 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.

[0223] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. 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, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1The 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 selected in one or more boxes.

[0224] 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 selected in one or more boxes.

[0225] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0226] 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.

[0227] 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, magnetic magnetic 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.

[0228] 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.

[0229] The above are merely embodiments of this disclosure and are not intended to limit the scope of this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of the claims of this disclosure.

Claims

1. A torque control method for a permanent magnet synchronous motor, characterized in that, Includes the following steps: Obtain the desired torque, feedback torque, and desired excitation current of the permanent magnet synchronous motor; Based on the desired torque, a first torque command current is obtained; based on the difference between the desired torque and the feedback torque, a second torque command current is obtained. The third torque command current is obtained based on the first torque command current and the second torque command current; Based on the desired excitation current and the preset linear compensation method, the third torque command current is linearly compensated to obtain the desired torque current of the permanent magnet synchronous motor. The permanent magnet synchronous motor is controlled to operate according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

2. The torque control method for a permanent magnet synchronous motor according to claim 1, characterized in that: The step of obtaining a first torque command current based on the desired torque, and obtaining a second torque command current based on the difference between the desired torque and the feedback torque, includes: The desired torque is input to the torque feedforward controller, so that the torque feedforward controller outputs the first torque command current based on the gain coefficient of the torque feedforward controller, the flux of the permanent magnet of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor, and the desired torque; wherein, when the desired torque remains unchanged, the first torque command current is linearly related to the gain coefficient of the torque feedforward controller. The difference between the desired torque and the feedback torque is input to the torque feedback controller, so that the torque feedback controller outputs the second torque command current based on the proportional coefficient, the integral coefficient, and the difference between the desired torque and the feedback torque. The proportional coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet synchronous motor, the number of pole pairs of the permanent magnet synchronous motor, the torque closed-loop response time parameter, and the excitation current closed-loop control time parameter. The integral coefficient of the torque feedback controller is obtained based on the magnetic flux of the permanent magnet synchronous motor, the number of pole pairs, and the torque closed-loop response time parameter.

3. The torque control method for a permanent magnet synchronous motor according to claim 2, characterized in that: The step of obtaining a third torque command current based on the first torque command current and the second torque command current includes: taking the sum of the first torque command current and the second torque command current as the third torque command current.

4. The torque control method for a permanent magnet synchronous motor according to claim 3, characterized in that: It also includes the following steps: Adjust the gain coefficient of the torque feedforward controller so that the torque feedforward controller independently controls the torque of the permanent magnet synchronous motor, the torque feedback controller independently controls the torque of the permanent magnet synchronous motor, the torque feedforward controller and the torque feedback controller control the torque of the permanent magnet synchronous motor in parallel, or adjust the torque control closed-loop time.

5. The torque control method for a permanent magnet synchronous motor according to claim 1, characterized in that: The desired torque current is obtained based on the desired excitation current, the direct-axis winding inductance of the permanent magnet synchronous motor, the quadrature-axis winding inductance of the permanent magnet synchronous motor, and the third torque command current; wherein, when the desired excitation current remains constant, the desired torque current and the third torque command current are linearly related.

6. The torque control method for a permanent magnet synchronous motor according to claim 1, characterized in that: The step of controlling the operation of the permanent magnet synchronous motor according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current, includes: Based on the offset difference between the feedback excitation current and the desired excitation current, and the offset difference between the feedback torque current and the desired torque current, the permanent magnet synchronous motor is controlled to operate, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

7. A torque control module for a permanent magnet synchronous motor, characterized in that, include: The data acquisition module is used to acquire the desired torque, feedback torque, and desired excitation current of the permanent magnet synchronous motor. The first current acquisition module is used to obtain a first torque command current based on the expected torque, and to obtain a second torque command current based on the difference between the expected torque and the feedback torque. The second current acquisition module is used to obtain the third torque command current based on the first torque command current and the second torque command current; The torque control module is used to linearly compensate the third torque command current according to the desired excitation current and a preset linear compensation method to obtain the desired torque current of the permanent magnet synchronous motor; and to control the operation of the permanent magnet synchronous motor according to the desired excitation current and the desired torque current, so that the torque of the permanent magnet synchronous motor is decoupled from the desired excitation current, and the torque of the permanent magnet synchronous motor changes with the change of the third torque command current.

8. An electronic device comprising a processor and a memory; characterized in that, The memory stores a computer program adapted to be loaded by the processor and executed as described in any one of claims 1 to 6 for torque control of a permanent magnet synchronous motor.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the torque control method for a permanent magnet synchronous motor as described in any one of claims 1 to 6.

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