Low-speed anti-disturbance control method and device for direct-drive permanent magnet synchronous motor system

Abstract

The invention relates to the technical field of direct-drive permanent magnet synchronous motor control, and discloses a low-speed anti-disturbance control method and device for a direct-drive permanent magnet synchronous motor system. The method comprises the following steps: S1, modeling a permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model conforming to a direct-drive permanent magnet synchronous motor system control standard; s2, establishing a load disturbance prediction controller of the direct-drive permanent magnet synchronous motor according to the mathematical model of the permanent magnet synchronous motor; and S3, performing disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and performing current loop feed-forward compensation according to the load disturbance prediction value at the next moment. Therefore, the problem that the system is often low in precision due to disturbance under the condition of low-speed control is solved, and the precision and the anti-disturbance capability of the system can be well improved through the method.

Description

Technical Field

[0001] The present invention relates to the technical field of direct-drive permanent magnet synchronous motor control, and in particular to a low-speed anti-disturbance control method and device for a direct-drive permanent magnet synchronous motor system. Background Art

[0002] Direct-drive permanent magnet synchronous motor system is one of the common operating forms in the industrial field. It is suitable for mechanical automation operations in many industrial fields, such as aerospace, CNC machine tools, inertial navigation and other high-precision control fields. Direct-drive permanent magnet synchronous motor system directly uses the motor to drive the load and uses high-precision permanent magnet synchronous motor to achieve high-precision control of the controlled object. PMSM (permanent magnet synchronous motor) has the advantages of small size, small inertia, fast response speed and high efficiency. However, due to the elimination of intermediate links such as reducers in traditional control, the system is often disturbed and has low accuracy under low-speed control, making it difficult to achieve satisfactory results. Summary of the invention

[0003] The present invention provides a low-speed anti-disturbance control method and device for a direct-drive permanent magnet synchronous motor system, which can solve the technical problems in the prior art.

[0004] The present invention provides a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system, wherein the method comprises:

[0005] S1. Modeling the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the direct drive permanent magnet synchronous motor system control standard, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation and the permanent magnet synchronous motor kinematic equation;

[0006] S2. According to the mathematical model of permanent magnet synchronous motor, a load disturbance prediction controller of direct drive permanent magnet synchronous motor is established;

[0007] S3. Perform disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and perform current loop feedforward compensation according to the load disturbance prediction value at the next moment.

[0008] Preferably, the voltage and current equations of the d-axis and q-axis of the permanent magnet synchronous motor are:

[0009]

[0010] Among them, u d 、u q Respectively represent the d-axis voltage and q-axis voltage, R srepresents the stator equivalent resistance, i d 、i q Respectively represent the d-axis current and q-axis current, ω e represents the motor electrical angular velocity at time t, L d , L q They represent the d-axis and q-axis inductance components, ψ d , q They are the d-axis and q-axis components of the motor stator flux respectively;

[0011] The transformation equations of the d-axis and q-axis currents of the permanent magnet synchronous motor in the rotating coordinate system are:

[0012]

[0013] Among them, i d 、i q Respectively represent the d-axis current and q-axis current, θ t represents the motor electrical angle at time t, i a 、i b 、i c represents the current in the natural coordinate system;

[0014] The magnetic flux equation is:

[0015]

[0016] Among them, ψ d , q are the d-axis and q-axis components of the motor stator flux, L d , L q Represent the d-axis and q-axis inductance components respectively, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux;

[0017] The electromagnetic torque equation of permanent magnet synchronous motor is:

[0018]

[0019] Among them, T e Represents the electromagnetic torque of the motor, p n is the number of motor pole pairs, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux, L d , L q Represent the d-axis and q-axis inductance components respectively;

[0020] The kinematic equation of permanent magnet synchronous motor is:

[0021]

[0022] Where J represents the motor moment of inertia, ω m Represents the motor mechanical angular velocity, T e Represents the electromagnetic torque of the motor, T R Indicates the total load torque of the system, T L Represents the motor load torque, T P represents the motor load disturbance value, and B represents the friction coefficient.

[0023] Preferably, the load disturbance prediction controller includes a load disturbance prediction unit and a feedforward control unit, and S3 performs disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment, including:

[0024] S31, performing disturbance prediction by the load disturbance prediction unit to obtain a load disturbance prediction value at the next moment;

[0025] S32. Perform feedforward compensation on the q-axis current according to the load disturbance prediction value at the next moment through the feedforward control unit.

[0026] Preferably, the load disturbance prediction unit includes a permanent magnet synchronous motor dq axis current prediction equation, a permanent magnet synchronous motor disturbance observation equation and a sliding mode reachability condition equation, wherein:

[0027] The prediction equation of the dq axis current of the permanent magnet synchronous motor is:

[0028]

[0029] Among them, i d k 、i q k represents the dq axis current at time k, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, λ d k , q k represents the dq axis current prediction factor at time k, u d k 、u q k represents the dq axis voltage at time k, ω e represents the electrical angular velocity of the motor at time k, L d , L q represents the dq axis inductance component, ψ f represents the total rotor flux, Δt represents the sampling period;

[0030] The state variables of the electrical angular velocity and the load disturbance of the permanent magnet synchronous motor at time k+1 are obtained by the following formula:

[0031]

[0032] in, represents the state variable of the motor electrical angular velocity at time k+1, represents the predicted value of the motor electrical angular velocity at time k+1, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, L d , L q represents the dq axis inductance component, ψ f Represents the total rotor flux, T L Represents the motor load torque, T P k+1 represents the predicted value of motor load disturbance at time k+1, The state variable representing the motor load disturbance at time k+1;

[0033] Perturbation observation equation of permanent magnet synchronous motor:

[0034]

[0035] in, The state variable representing the estimated value of the motor electrical angular velocity at time k+1, represents the estimated value of the motor load disturbance at time k+1, The state variable representing the estimated value of the motor load disturbance at time k+1, represents the estimated value of the motor angular velocity at time k+1, u s k+1 represents the sliding mode control rate at time k+1, K represents the sliding mode gain, and l represents the feedback gain;

[0036] The sliding mode reachability condition equation is:

[0037]

[0038] Among them, s k+1 represents the switching function, Indicates k+1 The state variable function, Represents the error between the estimated value and the actual value of the motor electrical angular velocity, express The state variables, represents the error between the estimated value and the actual value of the motor load disturbance at time k+1;

[0039] When the load disturbance prediction controller enters the sliding mode, The range of sliding mode gain K and feedback gain l is obtained by the following formula:

[0040]

[0041] Among them, c is the sliding mode adaptive adjustment parameter.

[0042] Preferably, the feedforward control unit includes a current compensation equation, which is:

[0043]

[0044] in, represents the estimated value of the motor load disturbance at time k+1, p n is the number of motor pole pairs, represents the predicted d-axis current at time k+1, i p represents the q-axis compensation current, ψ f is the total rotor flux, L d , L q Represent the d-axis and q-axis inductance components, I p Represents the disturbance feedforward compensation current.

[0045] The present invention also provides a low-speed anti-disturbance control device for a direct-drive permanent magnet synchronous motor system, wherein the device comprises:

[0046] A mathematical model building module is used to model the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the low-speed anti-disturbance control standard of the direct-drive permanent magnet synchronous motor system, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation and the permanent magnet synchronous motor kinematic equation;

[0047] A controller building module, used to establish a load disturbance prediction controller of a direct-drive permanent magnet synchronous motor according to the permanent magnet synchronous motor mathematical model;

[0048] The output module performs disturbance prediction according to the load disturbance prediction controller to obtain the load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment.

[0049] Through the above technical scheme, a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system can be provided, and a method for predicting load disturbances can be used in a traditional control model. This method solves the problem that the system often has low disturbance accuracy under low-speed control conditions. This method can greatly improve the system accuracy and anti-disturbance capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 A schematic flow chart of a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system according to an embodiment of the present invention is shown;

[0052] Figure 2 A control block diagram of a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system according to an embodiment of the present invention is shown;

[0053] Figure 3 is a control block diagram of a load disturbance prediction controller provided by an embodiment of the present invention;

[0054] Figure 4 It is a block diagram of a low-speed anti-disturbance control device for a direct-drive permanent magnet synchronous motor system provided by an embodiment of the present invention;

[0055] Figure 5 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0059] Figure 1 A schematic flow chart of a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system according to an embodiment of the present invention is shown.

[0060] like Figure 1 As shown, an embodiment of the present invention provides a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system, which can be implemented by an electronic device. The method includes:

[0061] S1. Modeling the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the direct drive permanent magnet synchronous motor system control standard, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation and the permanent magnet synchronous motor kinematic equation;

[0062] S2. According to the mathematical model of permanent magnet synchronous motor, a load disturbance prediction controller of direct drive permanent magnet synchronous motor is established;

[0063] S3. Perform disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and perform current loop feedforward compensation according to the load disturbance prediction value at the next moment.

[0064] Through the above technical scheme, a low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system can be provided, and a method for predicting load disturbances can be used in a traditional control model. This method solves the problem that the system often has low disturbance accuracy under low-speed control conditions. This method can greatly improve the system accuracy and anti-disturbance capability.

[0065] According to one embodiment of the present invention, the voltage and current equations of the d-axis and q-axis of the permanent magnet synchronous motor are:

[0066]

[0067] Among them, u d 、u q Respectively represent the d-axis voltage and q-axis voltage, R s represents the stator equivalent resistance, i d 、i q Respectively represent the d-axis current and q-axis current, ω e represents the motor electrical angular velocity at time t, L d , L q They represent the d-axis and q-axis inductance components, ψ d , q They are the d-axis and q-axis components of the motor stator flux respectively;

[0068] The transformation equations of the d-axis and q-axis currents of the permanent magnet synchronous motor in the rotating coordinate system are:

[0069]

[0070] Among them, i d 、i q Respectively represent the d-axis current and q-axis current, θ t represents the motor electrical angle at time t, i a 、i b 、i c represents the current in the natural coordinate system;

[0071] The magnetic flux equation is:

[0072]

[0073] Among them, ψ d , q are the d-axis and q-axis components of the motor stator flux, L d , L q Represent the d-axis and q-axis inductance components respectively, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux;

[0074] The electromagnetic torque equation of permanent magnet synchronous motor is:

[0075]

[0076] Among them, T e Represents the electromagnetic torque of the motor, p n is the number of motor pole pairs, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux, L d , L qRepresent the d-axis and q-axis inductance components respectively;

[0077] The kinematic equation of permanent magnet synchronous motor is:

[0078]

[0079] Where J represents the motor moment of inertia, ω m Represents the motor mechanical angular velocity, T e Represents the electromagnetic torque of the motor, T R Indicates the total load torque of the system, T L Represents the motor load torque, T P represents the motor load disturbance value, and B represents the friction coefficient.

[0080] According to an embodiment of the present invention, the load disturbance prediction controller includes a load disturbance prediction unit and a feedforward control unit, S3 performs disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment, including:

[0081] S31, performing disturbance prediction by the load disturbance prediction unit to obtain a load disturbance prediction value at the next moment;

[0082] S32. Perform feedforward compensation (current loop feedforward compensation) on the q-axis current according to the load disturbance prediction value at the next moment through the feedforward control unit.

[0083] Specifically, the dq axis current at time k is collected to predict the dq axis current at time k+1, a disturbance prediction observer is constructed according to the dq axis current at time k+1, and the load disturbance amount at the next time (load disturbance prediction value) is predicted.

[0084] According to an embodiment of the present invention, the load disturbance prediction unit includes a permanent magnet synchronous motor dq axis current prediction equation, a permanent magnet synchronous motor disturbance observation equation and a sliding mode reachability condition equation, wherein:

[0085] The prediction equation of the dq axis current of the permanent magnet synchronous motor is:

[0086]

[0087] Among them, i d k 、i q k represents the dq axis current at time k, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, λ d k ,q k represents the dq axis current prediction factor at time k, u d k 、u q k represents the dq axis voltage at time k, ω e represents the electrical angular velocity of the motor at time k, L d , L q represents the dq axis inductance component, ψ f represents the total rotor flux, Δt represents the sampling period;

[0088] The state variables of the electrical angular velocity and the load disturbance of the permanent magnet synchronous motor at time k+1 are obtained by the following formula:

[0089]

[0090] in, represents the state variable of the motor electrical angular velocity at time k+1, represents the predicted value of the motor electrical angular velocity at time k+1, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, L d , L q represents the dq axis inductance component, ψ f Represents the total rotor flux, T L Represents the motor load torque, T P k+1 represents the predicted value of motor load disturbance at time k+1, The state variable representing the motor load disturbance at time k+1 (considering that the disturbance is constant within the control period);

[0091] Perturbation observation equation of permanent magnet synchronous motor:

[0092]

[0093] in, The state variable representing the estimated value of the motor electrical angular velocity at time k+1, represents the estimated value of the motor load disturbance at time k+1, The state variable representing the estimated value of the motor load disturbance at time k+1, represents the estimated value of the motor angular velocity at time k+1, u s k+1 represents the sliding mode control rate at time k+1, K represents the sliding mode gain, and l represents the feedback gain;

[0094] The sliding mode reachability condition equation is:

[0095]

[0096] Among them, s k+1 represents the switching function, Indicates k+1 The state variable function, Represents the error between the estimated value and the actual value of the motor electrical angular velocity, express The state variables, represents the error between the estimated value and the actual value of the motor load disturbance at time k+1;

[0097] When the load disturbance prediction controller enters the sliding mode, The range of sliding mode gain K and feedback gain l is obtained by the following formula:

[0098]

[0099] Among them, c is the sliding mode adaptive adjustment parameter, which is a constant.

[0100] The feedforward control unit can perform feedforward compensation on the q-axis current according to the load disturbance prediction value, and can perform q-axis current compensation in a control method of vector control but not limited to vector control. The feedforward control unit can determine whether the load disturbance prediction value exceeds a set threshold (5% of the load, i.e. ), if it exceeds the set threshold, q-axis current feedforward compensation is performed.

[0101] According to an embodiment of the present invention, the feedforward control unit includes a current compensation equation, which is:

[0102]

[0103] in, represents the estimated value of the motor load disturbance at time k+1, p n is the number of motor pole pairs, represents the predicted d-axis current at time k+1, i p represents the q-axis compensation current, ψ f is the total rotor flux, L d , L q Represent the d-axis and q-axis inductance components, I p Represents the disturbance feedforward compensation current.

[0104] like Figure 2 As shown in the figure, it is the low-speed anti-disturbance control block diagram of the direct-drive permanent magnet synchronous motor system, where ω ref ,ω m Respectively represent the motor angular velocity given value and feedback value, I a ,I b ,Ic Represents the three-phase current of the motor in the natural coordinate system, I α ,I β represents the current in the stationary coordinate system, I d ,I q represents the dq axis current in the synchronous rotating coordinate system, Represents the current reference value of the vector control model, Output from the q-axis PI controller can be set

[0105] First, the angular velocity given value is subtracted from the motor angular velocity detected by the encoder to obtain the difference, and the q-axis reference current is output through the speed loop PI controller Secondly and disturbance feedforward compensation current I p The sum of q The difference is obtained by subtracting and the q-axis reference voltage is output through the current loop PI controller. with I d The difference is used to output the d-axis reference voltage through the current loop PI controller, and then it is combined with the q-axis reference voltage through static transformation and SVPWM operation to output six voltage vector control inverters, thereby controlling the motor operation.

[0106] like Figure 3 As shown in the figure, it is the control block diagram of the load disturbance prediction controller, where i d k+1 、i q k+1 It represents the predicted dq axis current at time k+1, represented by i d k 、i q k After current prediction, the output is obtained. It represents the predicted value of the motor electrical angular velocity at time k+1, which is calculated by the motor electrical angular velocity ω at time k. e and its derivative, Δt represents the sampling period which can be set according to the system requirements, ψ f represents the permanent magnet flux, T L Represents the motor load torque, is the output of the controller, which represents the predicted value of the motor load disturbance at time k+1.

[0107] like Figure 4 As shown, the embodiment of the present invention further provides a low-speed anti-disturbance control device 400 for a direct-drive permanent magnet synchronous motor system, wherein the device comprises:

[0108] A mathematical model building module 410 is used to model the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the low-speed anti-disturbance control standard of the direct-drive permanent magnet synchronous motor system, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation, and the permanent magnet synchronous motor kinematic equation;

[0109] A controller building module 420 is used to establish a load disturbance prediction controller of a direct-drive permanent magnet synchronous motor according to the permanent magnet synchronous motor mathematical model;

[0110] The output module 430 performs disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment.

[0111] Figure 5 1 is a schematic diagram of the structure of an electronic device 500 provided in an embodiment of the present invention. The electronic device 500 may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPU) 501 and one or more memories 502, wherein the memory 502 stores at least one instruction, and the at least one instruction is loaded and executed by the processor 501 to implement the following low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system:

[0112] S1. Model the permanent magnet synchronous motor to obtain a mathematical model of the permanent magnet synchronous motor that meets the control standard of the direct drive motor system;

[0113] S2. According to the mathematical model of permanent magnet synchronous motor, a load disturbance prediction controller of direct drive permanent magnet synchronous motor is established;

[0114] S3. Perform disturbance prediction according to the load disturbance prediction controller and perform current loop feedforward compensation according to the load disturbance prediction value.

[0115] It can be seen from the above embodiments that the low-speed anti-disturbance control method of the direct-drive permanent magnet synchronous motor system of the embodiment of the present invention includes: modeling the direct-drive permanent magnet synchronous motor system to obtain a permanent magnet synchronous motor mathematical model that meets the direct-drive motor system control standard; according to the permanent magnet synchronous motor mathematical model, a load disturbance prediction controller of the direct-drive permanent magnet synchronous motor is established; according to the load disturbance prediction controller, disturbance prediction is performed and current loop feedforward compensation is performed according to the load disturbance prediction value. The present invention can solve the problem that the system is often subject to low disturbance accuracy under low-speed control conditions, and greatly improve the system accuracy and anti-disturbance capability.

[0116] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0117] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0118] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0119] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-speed anti-disturbance control method for a direct-drive permanent magnet synchronous motor system, characterized in that: The method includes: S1. Modeling the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the direct drive permanent magnet synchronous motor system control standard, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation and the permanent magnet synchronous motor kinematic equation; S2. According to the mathematical model of permanent magnet synchronous motor, a load disturbance prediction controller of direct drive permanent magnet synchronous motor is established; S3. Perform disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and perform current loop feedforward compensation according to the load disturbance prediction value at the next moment.

2. The method according to claim 1, characterized in that The voltage and current equations of the d-axis and q-axis of the permanent magnet synchronous motor are: Among them, u d 、u q Respectively represent the d-axis voltage and q-axis voltage, R s represents the stator equivalent resistance, i d 、i q Respectively represent the d-axis current and q-axis current, ω e represents the motor electrical angular velocity at time t, L d , L q They represent the d-axis and q-axis inductance components, ψ d , q They are the d-axis and q-axis components of the motor stator flux respectively; The transformation equations of the d-axis and q-axis currents of the permanent magnet synchronous motor in the rotating coordinate system are: Among them, i d 、i q They represent the d-axis current and q-axis current respectively, θ t represents the motor electrical angle at time t, i a 、i b 、i c represents the current in the natural coordinate system; The magnetic flux equation is: Among them, ψ d , q are the d-axis and q-axis components of the motor stator flux, L d , L q Represent the d-axis and q-axis inductance components respectively, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux; The electromagnetic torque equation of permanent magnet synchronous motor is: Among them, T e Represents the electromagnetic torque of the motor, p n is the number of motor pole pairs, i d 、i q They represent the d-axis current and the q-axis current, respectively, f is the total rotor flux, L d , L q Represent the d-axis and q-axis inductance components respectively; The kinematic equation of permanent magnet synchronous motor is: Where J represents the motor moment of inertia, ω m Represents the motor mechanical angular velocity, T e Represents the electromagnetic torque of the motor, T R Indicates the total load torque of the system, T L Represents the motor load torque, T P represents the motor load disturbance value, and B represents the friction coefficient.

3. The method according to claim 2, characterized in that The load disturbance prediction controller includes a load disturbance prediction unit and a feedforward control unit. S3 performs disturbance prediction according to the load disturbance prediction controller to obtain a load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment, including: S31, performing disturbance prediction by the load disturbance prediction unit to obtain a load disturbance prediction value at the next moment; S32. Perform feedforward compensation on the q-axis current according to the load disturbance prediction value at the next moment through the feedforward control unit.

4. The method according to claim 3, characterized in that The load disturbance prediction unit includes a permanent magnet synchronous motor dq axis current prediction equation, a permanent magnet synchronous motor disturbance observation equation and a sliding mode reachable condition equation, wherein: The prediction equation of the dq axis current of the permanent magnet synchronous motor is: Among them, i d k 、i q k represents the dq axis current at time k, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, λ d k , q k represents the dq axis current prediction factor at time k, u d k 、u q k represents the dq axis voltage at time k, ω e represents the electrical angular velocity of the motor at time k, L d , L q represents the dq axis inductance component, ψ f represents the total rotor flux, Δt represents the sampling period; The state variables of the electrical angular velocity and the load disturbance of the permanent magnet synchronous motor at time k+1 are obtained by the following formula: in, represents the state variable of the motor electrical angular velocity at time k+1, represents the predicted value of the motor electrical angular velocity at time k+1, i d k+1 、i q k+1 represents the predicted dq axis current at time k+1, L d , L q represents the dq axis inductance component, ψ f Represents the total rotor flux, T L Represents the motor load torque, T P k+1 represents the predicted value of motor load disturbance at time k+1, The state variable representing the motor load disturbance at time k+1; Perturbation observation equation of permanent magnet synchronous motor: in, The state variable representing the estimated value of the motor electrical angular velocity at time k+1, represents the estimated value of the motor load disturbance at time k+1, The state variable representing the estimated value of the motor load disturbance at time k+1, represents the estimated value of the motor angular velocity at time k+1, u s k+1 represents the sliding mode control rate at time k+1, K represents the sliding mode gain, and l represents the feedback gain; The sliding mode reachability condition equation is: Among them, s k+1 represents the switching function, Indicates k+1 The state variable function, Represents the error between the estimated value and the actual value of the motor electrical angular velocity, express The state variables, represents the error between the estimated value and the actual value of the motor load disturbance at time k+1; When the load disturbance prediction controller enters the sliding mode, The range of sliding mode gain K and feedback gain l is obtained by the following formula: Among them, c is the sliding mode adaptive adjustment parameter.

5. The method according to claim 4, characterized in that The feedforward control unit includes a current compensation equation, which is: in, represents the estimated value of the motor load disturbance at time k+1, p n is the number of motor pole pairs, represents the predicted d-axis current at time k+1, i p represents the q-axis compensation current, ψ f is the total rotor flux, L d , L q Represent the d-axis and q-axis inductance components, I p Represents the disturbance feedforward compensation current.

6. A low-speed anti-disturbance control device for a direct-drive permanent magnet synchronous motor system, characterized in that: The device comprises: A mathematical model building module is used to model the permanent magnet synchronous motor to obtain a permanent magnet synchronous motor mathematical model that meets the low-speed anti-disturbance control standard of the direct-drive permanent magnet synchronous motor system, wherein the permanent magnet synchronous motor mathematical model includes the permanent magnet synchronous motor d-axis and q-axis voltage and current equations, the permanent magnet synchronous motor d-axis and q-axis current transformation equations in the rotating coordinate system, the flux equation, the permanent magnet synchronous motor electromagnetic torque equation and the permanent magnet synchronous motor kinematic equation; A controller building module, used to establish a load disturbance prediction controller of a direct-drive permanent magnet synchronous motor according to the permanent magnet synchronous motor mathematical model; The output module performs disturbance prediction according to the load disturbance prediction controller to obtain the load disturbance prediction value at the next moment, and performs current loop feedforward compensation according to the load disturbance prediction value at the next moment.

Images