Motor control method and device, compressor and storage medium

Abstract

The application discloses a motor control method and device, a compressor and a storage medium, wherein the method comprises the following steps: obtaining dq-axis currents of a controlled motor based on a discrete-domain controlled motor model, and determining dq-axis flux linkage observation values of the controlled motor according to the dq-axis currents of the controlled motor; performing two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observation values respectively, so as to obtain dq-axis voltage reference values according to two-degree-of-freedom PI control signals and discrete-domain state prediction feedback control signals; obtaining dq-axis voltage vector command values according to the dq-axis voltage reference values, and performing driving control on the controlled motor according to the dq-axis voltage vector command values. Therefore, the dq-axis flux linkage observation values are obtained based on the discrete-domain controlled motor model, and a discrete-domain state feedback control framework is constructed by combining the two-degree-of-freedom characteristics of the two-degree-of-freedom PI control and the discrete-domain state prediction feedback, so that the high-bandwidth tracking capability and the operation stability of the compressor in the full-frequency domain operation are ensured.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a motor control method, a motor control device, a compressor, and a computer-readable storage medium. Background Technology

[0002] PI-type current regulators based on synchronous reference coordinates have become the standard method for AC motor current regulation. However, the speed-related cross-coupling terms they generate severely restrict the effective bandwidth and stability of the controller in low carrier ratio control. Digital control delays (sampling and calculation delays) significantly degrade the compressor's high-speed operation capability and load disturbance resistance. Currently, discrete-domain active damped complex vector regulators with delay compensation are the mainstream low carrier ratio current regulator solutions. However, for compressor motor control applications, on the one hand, the compressor's heavy-load saturation nonlinear parameter errors prevent the discrete-domain complex vector model from accurately modeling saturation nonlinearity. On the other hand, high-power-density compressor motors generally have salient pole characteristics, and the improved salient pole model structure based on discrete-domain complex vectors is too complex for application in air conditioning products. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, the first objective of this invention is to propose a motor control method that can obtain dq-axis flux linkage observations based on a discrete-domain controlled motor model, and utilize the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, thereby ensuring the compressor's high bandwidth tracking capability and operational stability across the entire frequency domain.

[0004] The second objective of this invention is to provide a motor control device.

[0005] The third objective of this invention is to provide a compressor.

[0006] The fourth objective of this invention is to provide a computer-readable storage medium.

[0007] To achieve the above objectives, the motor control method proposed in the first aspect of the present invention includes: obtaining the dq-axis current of the controlled motor based on a discrete-domain controlled motor model, and determining the dq-axis flux linkage observation value of the controlled motor based on the dq-axis current; performing two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observation value respectively, obtaining a two-degree-of-freedom PI control signal and a discrete-domain state prediction feedback control signal, and obtaining a dq-axis voltage reference value based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal; obtaining a dq-axis voltage vector command value based on the dq-axis voltage reference value, and performing drive control on the controlled motor based on the dq-axis voltage vector command value.

[0008] According to the motor control method of this invention, the dq-axis current of the controlled motor is obtained based on a discrete-domain controlled motor model, and the observed dq-axis flux linkage of the controlled motor is determined based on the dq-axis current. Then, two-degree-of-freedom PI control and discrete-domain state prediction feedback control are applied to the observed dq-axis flux linkage to obtain two-degree-of-freedom PI control signals and discrete-domain state prediction feedback control signals. Based on the two-degree-of-freedom PI control signals and discrete-domain state prediction feedback control signals, a dq-axis voltage reference value is obtained. Finally, a dq-axis voltage vector command value is obtained based on the dq-axis voltage reference value, and the controlled motor is driven and controlled based on the dq-axis voltage vector command value. Thus, by obtaining the observed dq-axis flux linkage based on the discrete-domain controlled motor model and utilizing the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, a high-bandwidth tracking capability and operational stability of the compressor across the entire frequency domain are ensured.

[0009] In addition, the motor control method according to the above embodiments of the present invention may also have the following additional technical features:

[0010] According to an embodiment of the present invention, the discrete-domain controlled motor model is designed as follows:

[0011] in, Let dq be the dq-axis current corresponding to the dq-axis flux linkage at time k+1. Let be the dq-axis current of the dq-axis flux linkage at time k. This is the difference between the total voltage across the dq axis and the back electromotive force voltage across the dq axis.

[0012] According to an embodiment of the present invention, the step of performing two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observation value to obtain the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal includes: performing two-degree-of-freedom PI control on the difference between the dq-axis flux linkage observation value and the dq-axis flux linkage reference value to obtain the two-degree-of-freedom PI control signal; and inputting the dq-axis flux linkage observation value into the discrete-domain forward one-step prediction model to obtain the discrete-domain state prediction feedback control signal.

[0013] According to an embodiment of the present invention, the discrete-domain forward one-step prediction model is designed as follows: in, Let k be the predicted flux linkage along the dq axis. U is the observed flux linkage along the dq axis at time k-1. dq (k-1) represents the dq-axis voltage value at time k-1.

[0014] According to an embodiment of the present invention, the dq-axis voltage reference value is obtained by the following formula: Among them, u ref (k) is the reference value for the dq-axis voltage. It is a two-degree-of-freedom PI control signal. For discrete-domain state prediction feedback control signal, Ψ dq_ref (k) represents the reference value of the dq-axis flux linkage at time k. This represents the predicted flux linkage value along the dq axis at time k+1. Let K be the observed flux linkage along the dq axis at time k. ff For reference feedforward gain, K A For state prediction feedback gain, K i This is the integral gain.

[0015] According to an embodiment of the present invention, before driving the controlled motor according to the dq-axis voltage vector command value, the method further includes: inputting the dq-axis voltage vector command value into a control voltage compensation model to obtain a compensated dq-axis voltage vector command value; and driving the controlled motor according to the compensated dq-axis voltage vector command value.

[0016] According to one embodiment of the present invention, the control voltage compensation model is designed as follows: in, The compensated dq-axis voltage vector command value. This is the command value for the dq-axis voltage vector.

[0017] To achieve the above objectives, a motor control device according to a second aspect embodiment of the present invention includes: a first acquisition module, configured to acquire the dq-axis current of the controlled motor based on a discrete-domain controlled motor model, and determine the dq-axis flux linkage observation value of the controlled motor based on the dq-axis current; a second acquisition module, configured to perform two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observation value respectively, acquire a two-degree-of-freedom PI control signal and a discrete-domain state prediction feedback control signal, and acquire the dq-axis voltage reference value based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal; and a control module, configured to acquire the dq-axis voltage vector command value based on the dq-axis voltage reference value, and perform drive control on the controlled motor based on the dq-axis voltage vector command value.

[0018] According to an embodiment of the present invention, the motor control device acquires the dq-axis current of the controlled motor based on a discrete-domain controlled motor model through a first acquisition module, and determines the observed dq-axis flux linkage value of the controlled motor based on the dq-axis current. Then, a second acquisition module performs two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the observed dq-axis flux linkage value, respectively, to acquire the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal. Based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, a dq-axis voltage reference value is acquired. Finally, a control module acquires the dq-axis voltage vector command value based on the dq-axis voltage reference value, and performs drive control on the controlled motor based on the dq-axis voltage vector command value. Thus, by acquiring the observed dq-axis flux linkage value based on the discrete-domain controlled motor model, and utilizing the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, a high-bandwidth tracking capability and operational stability of the compressor across the entire frequency domain are ensured.

[0019] To achieve the above objectives, a compressor according to a third aspect embodiment of the present invention includes: a motor control device as described in the above embodiments of the present invention; or, a processor, a memory, and a motor control program stored in the memory and executable on the processor, wherein the motor control program, when executed by the processor, implements the motor control method as described in the above embodiments of the present invention.

[0020] According to embodiments of the present invention, the compressor can obtain the observed values ​​of the dq-axis flux linkage based on the discrete domain controlled motor model, and utilize the dual-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete domain state prediction feedback to construct a discrete domain state feedback control framework, thereby ensuring the high bandwidth tracking capability and operational stability of the compressor in the full frequency domain.

[0021] To achieve the above objectives, a computer-readable storage medium according to a fourth aspect embodiment of the present invention stores a motor control program, which, when executed by a processor, implements the motor control method of the present invention as described above.

[0022] According to embodiments of the present invention, a computer-readable storage medium can obtain dq-axis flux linkage observations based on a discrete-domain controlled motor model, and utilize the dual-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, thereby ensuring the high bandwidth tracking capability and operational stability of the compressor in the full frequency domain.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] Figure 1This is a schematic flowchart of a motor control method according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the control principle of a motor control method according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic flowchart of a motor control method according to an embodiment of the present invention;

[0027] Figure 4 This is a block diagram of a motor control device according to an embodiment of the present invention. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The following description, with reference to the accompanying drawings, describes an embodiment of the present invention, including a motor control method, a motor control device, a compressor, and a computer-readable storage medium.

[0030] Figure 1 This is a schematic flowchart of a motor control method according to an embodiment of the present invention.

[0031] Specifically, in some embodiments of the present invention, such as Figure 1 As shown, the motor control method includes:

[0032] S101. Obtain the dq-axis current of the controlled motor based on the discrete domain controlled motor model, and determine the observed value of the dq-axis flux linkage of the controlled motor based on the dq-axis current of the controlled motor.

[0033] It is understood that, in this embodiment of the present invention, as Figure 2 As shown, the dq-axis current i of the controlled motor can be obtained first based on the discrete domain controlled motor model. dq Then based on the dq axis current i dq The magnetic flux linkage observation Ψ along the dq axis dq The conversion relationship between i dq (Ψ) represents the dq-axis current i of the controlled motor. dq Convert to dq axis flux linkage observation Ψ dq .

[0034] It should be noted that in the above embodiments of the present invention, based on the saturated nonlinear state change from current to flux linkage, the flux linkage signal is selected as the state feedback variable of the control system. This is applicable to highly saturated compressor permanent magnet motors and compatible with the salient pole characteristics of compressor motors. Furthermore, a discrete domain controlled motor model is established based on the flux linkage state.

[0035] Optionally, in some embodiments of the present invention, the discrete-domain controlled motor model is designed as follows:

[0036]

[0037] in, This represents the predicted dq-axis current value for the dq-axis flux linkage at time k+1. Let be the dq-axis feedback current value of the dq-axis flux linkage at time k. denoted as dq, where dq is the difference between the reference average voltage and the back electromotive force voltage of the dq axis; r is the stator resistance of the motor; ld is the direct-axis inductance of the stator of the motor; lq is the quadrature-axis inductance of the stator of the motor; Ts represents the control time period; φf is the rotor flux linkage of the motor; and ωe is the electronic rotor frequency.

[0038] To model the built-in permanent magnet synchronous motor, the stator current vector is defined as i s =[i d i q ] T , where i d and i q These are the components of the current vector. The matrix transpose is represented by the superscript T, and the identity matrix is ​​defined as I.

[0039] Therefore, when the stator current vector is chosen as the state variable, the state equation is constructed as follows:

[0040]

[0041] Among them, i s (t) represents the stator current signal, u s (t) represents the electronic voltage signal. This is for differential operations.

[0042] Wherein, the input is the stator voltage vector u s (t) and PM magnetic flux ψ f (Constant), then the system matrix is:

[0043]

[0044] Among them, R S L is the stator resistance. d For a direct-axis inductor, L qFor orthogonal axis inductance, ω m Here is the rotor frequency value of the motor, and the subscript c indicates the continuous-time model.

[0045] It should be understood that, in the prior art, PI-type current regulators based on synchronous reference coordinates have become the standard method for AC motor current regulation. The speed-related cross-coupling terms generated by these regulators severely restrict the effective bandwidth and stability of the controller in low carrier ratio control. Digital control delays (sampling process and calculation delays) will severely degrade the compressor's high-speed operation capability and load disturbance resistance. Therefore, in this embodiment of the present invention, in order to design the current controller directly in the discrete-time domain, the discrete-domain controlled motor model is designed as follows:

[0046]

[0047] S102 performs two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the observed flux linkage values ​​of the dq axis respectively, obtains the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, and obtains the reference value of the dq axis voltage based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal.

[0048] It is understood that in this embodiment of the present invention, a discrete-domain state feedback control framework is constructed by utilizing the two-degree-of-freedom characteristics of PI control combined with discrete-domain state prediction feedback. The two-degree-of-freedom PI control includes a reference feedforward control section (combined with the reference feedforward gain K). ff ) and PI integral feedback control section (combined with integral gain K) i To output a two-degree-of-freedom PI control signal. Discrete-domain state prediction feedback control includes the precise discrete-domain prediction of the flux linkage state to obtain the one-step forward dq-axis flux linkage prediction value in the discrete domain. Then, combine the state feedback gain K A As the state feedback control part of the low carrier ratio controller, it outputs a discrete-domain state prediction feedback control signal. Finally, based on the two-degree-of-freedom PI control signal Discrete-domain state prediction feedback control signal Obtain the dq axis voltage reference value u ref (k).

[0049] Optionally, in some embodiments of the present invention, the dq-axis voltage reference value is obtained by the following formula:

[0050]

[0051] Among them, u ref (k) is the reference value for the dq-axis voltage. It is a two-degree-of-freedom PI control signal. For discrete-domain state prediction feedback control signal, Ψ dq_ref (k) represents the reference value of the dq-axis flux linkage at time k. This represents the predicted flux linkage along the dq axis at time k+1. Let K be the dq-axis flux linkage observation at time k. ff For reference feedforward gain, K A For state prediction feedback gain, K i This is the integral gain.

[0052] It is understood that, in this embodiment of the invention, similar to a continuous-time design, the stator current is mapped onto the flux linkage. Furthermore, a state feedback controller with integral internal mode and reference feedforward is applied. Therefore, the dq-axis voltage reference value is obtained as follows:

[0053] As can be seen, discrete-time control design is very similar to continuous-time design. Continuous-time design considers computational delay, while discrete-time design uses K... A If the delay is considered in this way, then the corresponding gain matrix K i K ff K A It can be solved as a function of the coefficient matrix; therefore, the closed-loop transfer function matrix u can be derived. ref (k) Simplified to the following standard form:

[0054]

[0055] In addition, the inherent periodic disturbances of the compressor load are another factor to consider for the low-carrier controller. Therefore, the resistance of the designed discrete-domain controller and its damping compensation design strategy to compressor disturbances is further analyzed, where u i (s)=[0,ω e ·ψ f The voltage is generated by the magnetic flux induction of the PM, i.e., the voltage disturbance generated by the compressor. This disturbance is used as the interference term in the current controller. Therefore, the derivation result of the disturbance rejection transfer function of the designed controller is as follows:

[0056]

[0057] Among them, Z -1 Let G be the discrete-domain unit delay factor, K be the discrete-domain equivalent gain parameter, and G be the discrete-domain equivalent gain parameter. c (Z) represents the discrete-domain controller transfer model, G p (Z) is the transfer function of the discrete-domain controlled model, ω e T is the rotor frequency value of the motor. s To control the time period, This is an adjustable damping transfer function.

[0058] As can be seen, for the designed controller, considering the influence of the compressor periodic disturbance voltage characteristics, the dominant poles that determine the closed-loop bandwidth characteristics of the control system remain intact. As the carrier ratio continues to deteriorate, the zero-pole cancellation effect remains intact, and other zeros and poles that affect the system's anti-disturbance performance have achieved good cancellation effects, ensuring the resistance to compressor load disturbances and system stability under low carrier conditions.

[0059] S103: Obtain the dq axis voltage vector command value based on the dq axis voltage reference value, and perform drive control on the controlled motor based on the dq axis voltage vector command value.

[0060] It is understood that, in this embodiment of the present invention, the dq axis voltage vector command value can be determined by the dq axis voltage reference value, and then the controlled motor can be driven to work based on the dq axis voltage vector command value.

[0061] Furthermore, in some embodiments of the present invention, two-degree-of-freedom PI control and discrete-domain state prediction feedback control are performed on the dq-axis flux linkage observation values ​​to obtain two-degree-of-freedom PI control signals and discrete-domain state prediction feedback control signals, including: performing two-degree-of-freedom PI control on the difference between the dq-axis flux linkage observation value and the dq-axis flux linkage reference value to obtain a two-degree-of-freedom PI control signal; and inputting the dq-axis flux linkage observation value into the discrete-domain forward one-step prediction model to obtain a discrete-domain state prediction feedback control signal.

[0062] It is understood that, in this embodiment of the invention, the dq-axis flux linkage observation value is used... and dq axis flux linkage reference value Ψ dq_ref The difference (k) is used as the input of the two-degree-of-freedom PI control to obtain the output of the two-degree-of-freedom PI control, i.e., the two-degree-of-freedom PI control signal. Meanwhile, by observing the dq axis flux linkage As input to the discrete-domain forward one-beat prediction model, the predicted values ​​of the dq-axis flux linkages in the discrete-domain forward one-beat prediction are obtained. Furthermore, combining the state prediction feedback gain K A To obtain discrete-domain state prediction feedback control signals

[0063] Optionally, in some embodiments of the present invention, the discrete-domain forward one-beat prediction model is designed as follows:

[0064]

[0065] in, Let k be the predicted flux linkage along the dq axis. U is the observed flux linkage along the dq axis at time k-1. dq (k-1) is the reference value of the dq-axis voltage at time k-1, ω e T is the rotor frequency value of the motor. s To control the time period.

[0066] It is understood that in this embodiment of the present invention, by establishing the direct discrete domain flux linkage voltage prediction equation, the observed flux linkage signal is accurately predicted in one step, which fundamentally solves the problem that the traditional controller is limited by the influence of the one-beat control delay under low carrier ratio conditions and cannot effectively improve the system's anti-interference performance. This ensures the comprehensive improvement of the compressor's anti-periodic interference performance under low carrier ratio conditions and greatly improves the operating stability of the compressor system.

[0067] Specifically, based on the average voltage model of the PWM inverter in the reference coordinate system shown in the above formula, the precise hold-equivalent discrete-time model in the rotor coordinate system can be derived as follows:

[0068] ψ(k+1)=Φψ(k)+T s Φu(k),

[0069] Where Ts is the sampling period and u(k) is the current reference value of the controller voltage vector.

[0070] Using the current flux linkage observation ψ(k) along the dq axis as the input to the discrete-domain forward one-step prediction model, the state transition matrix for the dq axis flux linkage prediction ψ(k+1) in the discrete-domain forward one-step prediction is as follows:

[0071] Φ=exp(-T s ω em J), where,

[0072] Due to limited computation time, digital control systems typically have a sampling period that remains constant, i.e.: u s (k)=u sref (k-1), where Us(k) is the current controller voltage vector reference value, and Usref(k-1) is the controller voltage vector reference value of the previous control cycle.

[0073] Therefore, the discrete-domain forward one-step prediction model based on flux linkage state can be designed as follows:

[0074]

[0075] Furthermore, in some embodiments of the present invention, such as Figure 3 As shown, before driving the controlled motor according to the dq axis voltage vector command value, the method further includes:

[0076] S201, input the dq axis voltage vector command value to the control voltage compensation model, and obtain the compensated dq axis voltage vector command value.

[0077] It is understandable that due to the delay characteristics of the actual physical system implementation, there is a deviation between the actual voltage vector and the command value. Therefore, in this embodiment of the present invention, the dq-axis voltage vector command value is corrected by inputting the dq-axis voltage vector command value into the control voltage compensation model in order to obtain the compensated dq-axis voltage vector command value.

[0078] S202 drives the controlled motor according to the compensated dq axis voltage vector command value.

[0079] It is understood that in this embodiment of the present invention, the controlled motor is driven and controlled by a more accurate dq-axis voltage vector command value after compensation, thereby ensuring the reliability and control stability of the controlled motor.

[0080] Optionally, in some embodiments of the present invention, the control voltage compensation model is designed as follows:

[0081]

[0082] in, The compensated dq-axis voltage vector command value. This is the command value for the dq-axis voltage vector.

[0083] It is understood that, in this embodiment of the present invention, the voltage vector command value V obtained by the average current controller dq =V d +j*V q , where V d V is the direct-axis component of the voltage vector. q The cross-axis component of the voltage vector, and then, through the control voltage compensation model. To obtain the compensated dq-axis voltage vector command value V dq_mean =V dq_mean +j*V dq_mean Where Vd_mean is the direct-axis component of the voltage vector, Vq_mean is the cross-axis component of the voltage vector, and β ranges from 0 to 1, with a preferred value of 0.5, which is equivalent to simulating the delay characteristics of a real physical system.

[0084] In summary, the motor control method according to embodiments of the present invention obtains the dq-axis current of the controlled motor based on a discrete-domain controlled motor model, determines the observed dq-axis flux linkage value of the controlled motor based on the dq-axis current, and then performs two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the observed dq-axis flux linkage value to obtain the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal. Based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, a dq-axis voltage reference value is obtained. Finally, a dq-axis voltage vector command value is obtained based on the dq-axis voltage reference value, and the controlled motor is driven and controlled based on the dq-axis voltage vector command value. Therefore, by obtaining the observed dq-axis flux linkage value based on the discrete-domain controlled motor model and utilizing the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, the high bandwidth tracking capability and operational stability of the compressor in the full frequency domain are ensured.

[0085] Figure 4 This is a block diagram of a motor control device according to an embodiment of the present invention.

[0086] Specifically, in some embodiments of the present invention, such as Figure 4 As shown, the motor control device 100 includes: a first acquisition module 10, a second acquisition module 20, and a control module 30.

[0087] The first acquisition module 10 is used to acquire the dq-axis current of the controlled motor based on the discrete domain controlled motor model, and determine the dq-axis flux linkage observation value of the controlled motor based on the dq-axis current; the second acquisition module 20 is used to perform two-degree-of-freedom PI control and discrete domain state prediction feedback control on the dq-axis flux linkage observation value respectively, acquire the two-degree-of-freedom PI control signal and the discrete domain state prediction feedback control signal, and acquire the dq-axis voltage reference value based on the two-degree-of-freedom PI control signal and the discrete domain state prediction feedback control signal; the control module 30 is used to acquire the dq-axis voltage vector command value based on the dq-axis voltage reference value, and perform drive control on the controlled motor based on the dq-axis voltage vector command value.

[0088] Furthermore, in some embodiments of the present invention, the discrete-domain controlled motor model is designed as follows:

[0089] in, Let dq be the dq-axis current corresponding to the dq-axis flux linkage at time k+1. Let be the dq-axis current of the dq-axis flux linkage at time k. This is the difference between the total voltage across the dq axis and the back electromotive force voltage across the dq axis.

[0090] Furthermore, in some embodiments of the present invention, the second acquisition module 20 is also used to perform two-degree-of-freedom PI control on the difference between the observed value of the dq-axis flux linkage and the reference value of the dq-axis flux linkage to acquire a two-degree-of-freedom PI control signal, and to input the observed value of the dq-axis flux linkage to the discrete domain forward one-step prediction model to acquire a discrete domain state prediction feedback control signal.

[0091] Furthermore, in some embodiments of the present invention, the discrete-domain forward one-beat prediction model is designed as follows: in, Let k be the predicted flux linkage along the dq axis. U is the observed flux linkage along the dq axis at time k-1. da (k-1) represents the dq-axis voltage value at time k-1.

[0092] Furthermore, in some embodiments of the present invention, the dq-axis voltage reference value is obtained using the following formula: Among them, u ref (k) is the reference value for the dq-axis voltage. It is a two-degree-of-freedom PI control signal. For discrete-domain state prediction feedback control signal, Ψ dq_ref (k) represents the reference value of the dq-axis flux linkage at time k. This represents the predicted flux linkage along the dq axis at time k+1. Let K be the dq-axis flux linkage observation at time k. ff For reference feedforward gain, K A For state prediction feedback gain, K i This is the integral gain.

[0093] Furthermore, in some embodiments of the present invention, the control module 30 is further configured to input the dq-axis voltage vector command value into the control voltage compensation model to obtain the compensated dq-axis voltage vector command value before driving the controlled motor according to the dq-axis voltage vector command value; and drive the controlled motor according to the compensated dq-axis voltage vector command value.

[0094] Furthermore, in some embodiments of the present invention, the control voltage compensation model is designed as follows: in, The compensated dq-axis voltage vector command value. This is the command value for the dq-axis voltage vector.

[0095] It should be understood that the specific implementation of the motor control device in the embodiments of the present invention corresponds one-to-one with the specific implementation of the motor control method in the foregoing embodiments of the present invention. To reduce redundancy, it will not be described again here.

[0096] In summary, the motor control device according to embodiments of the present invention acquires the dq-axis current of the controlled motor based on a discrete-domain controlled motor model through a first acquisition module, and determines the observed dq-axis flux linkage value of the controlled motor based on the dq-axis current. Then, a second acquisition module performs two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the observed dq-axis flux linkage value to acquire the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal. Based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, a dq-axis voltage reference value is acquired. Finally, a control module acquires the dq-axis voltage vector command value based on the dq-axis voltage reference value and performs drive control on the controlled motor based on the dq-axis voltage vector command value. Thus, by acquiring the observed dq-axis flux linkage value based on a discrete-domain controlled motor model and utilizing the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, the high bandwidth tracking capability and operational stability of the compressor across the entire frequency domain are ensured.

[0097] Based on the motor control device or motor control method of the foregoing embodiments of the present invention, the present invention also proposes a compressor, including: the motor control device of the foregoing embodiments of the present invention; or, a processor, a memory, and a motor control program stored in the memory and executable on the processor, wherein the motor control program implements the motor control method of the foregoing embodiments of the present invention when executed by the processor.

[0098] It should be understood that the specific implementation of the compressor in the embodiments of the present invention can refer to the specific implementation of the motor control method in the foregoing embodiments of the present invention, and will not be repeated here to reduce redundancy.

[0099] In summary, the compressor according to the present invention can obtain the dq axis flux linkage observation value based on the discrete domain controlled motor model, and use the two-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete domain state prediction feedback to construct a discrete domain state feedback control framework, thereby ensuring the high bandwidth tracking capability and operational stability of the compressor in the full frequency domain.

[0100] Based on the motor control method of the foregoing embodiments of the present invention, the present invention also proposes a computer-readable storage medium storing a motor control program, which, when executed by a processor, implements the motor control method of the foregoing embodiments of the present invention.

[0101] It should be understood that the specific implementation of the computer-readable storage medium in the embodiments of the present invention can be found in the specific implementation of the motor control method in the foregoing embodiments of the present invention, and will not be repeated here to reduce redundancy.

[0102] In summary, the computer-readable storage medium according to embodiments of the present invention can obtain the dq-axis flux linkage observations based on a discrete-domain controlled motor model, and utilize the dual-degree-of-freedom characteristics of two-degree-of-freedom PI control combined with discrete-domain state prediction feedback to construct a discrete-domain state feedback control framework, thereby ensuring the high bandwidth tracking capability and operational stability of the compressor in the full frequency domain.

[0103] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0104] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0105] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0106] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0107] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0108] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0109] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0110] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor control method, characterized in that, The method includes: The dq-axis current of the controlled motor is obtained based on the discrete domain controlled motor model, and the dq-axis flux linkage observation value of the controlled motor is determined based on the dq-axis current of the controlled motor. The observed flux linkage values ​​of the dq axis are subjected to two-degree-of-freedom PI control and discrete-domain state prediction feedback control respectively to obtain the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal. Based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, the reference value of the dq axis voltage is obtained. The dq axis voltage vector command value is obtained based on the dq axis voltage reference value, and the controlled motor is driven and controlled based on the dq axis voltage vector command value.

2. The motor control method according to claim 1, characterized in that, The discrete-domain controlled motor model is designed as follows: in, Let dq be the dq-axis current corresponding to the dq-axis flux linkage at time k+1. Let be the dq-axis current of the dq-axis flux linkage at time k. This is the difference between the total voltage across the dq axis and the back electromotive force voltage across the dq axis.

3. The motor control method according to claim 2, characterized in that, The step of performing two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observations to obtain the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal includes: The difference between the observed dq-axis flux linkage and the reference dq-axis flux linkage is subjected to two-degree-of-freedom PI control to obtain the two-degree-of-freedom PI control signal. The observed dq-axis flux linkage is then input into a discrete-domain forward one-step prediction model to obtain the discrete-domain state prediction feedback control signal.

4. The motor control method according to claim 3, characterized in that, The discrete-domain forward one-step prediction model is designed as follows: in, Let k be the predicted flux linkage along the dq axis. U is the observed flux linkage along the dq axis at time k-1. dq (k-1) represents the dq-axis voltage value at time k-1.

5. The motor control method according to claim 3, characterized in that, The dq axis voltage reference value is obtained using the following formula: Among them, u ref (k) is the reference value for the dq-axis voltage. It is a two-degree-of-freedom PI control signal. For discrete-domain state prediction feedback control signal, Ψ dq_ref (k) represents the reference value of the dq-axis flux linkage at time k. This represents the predicted flux linkage value along the dq axis at time k+1. Let K be the observed flux linkage along the dq axis at time k. ff For reference feedforward gain, K A For state prediction feedback gain, K i This is the integral gain.

6. The motor control method according to claim 1, characterized in that, Before driving the controlled motor according to the dq axis voltage vector command value, the method further includes: The dq-axis voltage vector command value is input into the control voltage compensation model to obtain the compensated dq-axis voltage vector command value. The controlled motor is driven and controlled according to the compensated dq axis voltage vector command value.

7. The motor control method according to claim 6, characterized in that, The control voltage compensation model is designed as follows: in, The compensated dq-axis voltage vector command value. This is the command value for the dq-axis voltage vector.

8. A motor control device, characterized in that, The device includes: The first acquisition module is used to acquire the dq-axis current of the controlled motor based on the discrete domain controlled motor model, and to determine the dq-axis flux linkage observation value of the controlled motor based on the dq-axis current of the controlled motor. The second acquisition module is used to perform two-degree-of-freedom PI control and discrete-domain state prediction feedback control on the dq-axis flux linkage observation values ​​respectively, acquire the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal, and acquire the dq-axis voltage reference value based on the two-degree-of-freedom PI control signal and the discrete-domain state prediction feedback control signal. The control module is used to obtain the dq axis voltage vector command value based on the dq axis voltage reference value, and to drive the controlled motor according to the dq axis voltage vector command value.

9. A compressor, characterized in that, include: The motor control device as described in claim 8; Alternatively, a processor, a memory, and a motor control program stored in the memory and executable on the processor, wherein the motor control program, when executed by the processor, implements the motor control method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a motor control program, which, when executed by a processor, implements the motor control method as described in any one of claims 1-7.

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