Robust predictive current control method and system for linear oscillatory motor

Abstract

The application relates to the technical field of motor driving and control, and discloses a robust predictive current control method and system for a linear oscillation motor. The method first constructs virtual orthogonal components of single-phase electrical quantities of the linear oscillation motor to form a virtual two-phase stationary coordinate system, performs Park transformation by using a synchronous rotation angle, constructs a displacement directional synchronous rotation coordinate system of a shaft alignment mover displacement vector, and obtains shaft current components, shaft current components and original reference values thereof in the displacement directional synchronous rotation coordinate system. The method can inhibit steady-state current deviation caused by parameter mismatch without online identification or direct correction of motor model parameters, can maintain a resonance operation state under parameter variation conditions and improve mover stroke control precision, and is suitable for reciprocating motion driving occasions such as linear compressors and Stirling refrigerators.

Description

Technical Field

[0001] This invention belongs to the field of motor drive and control technology, specifically relating to a robust predictive current control method and system for a linear oscillating motor. Background Technology

[0002] Linear oscillating motors can directly generate reciprocating linear motion, eliminating the need for intermediate transmission mechanisms such as crankshafts and connecting rods. They have advantages such as compact structure, low friction loss, high power density, and short energy conversion chain, and have been widely used in reciprocating motion drive applications such as linear compressors and Stirling refrigerators.

[0003] In the aforementioned applications, linear oscillating motors are typically directly connected to the piston or load mechanism. Since there is usually a lack of rigid mechanical limits in the direction of the mover's movement, cylinder collisions or structural damage can easily occur when the transient stroke exceeds the safe range. Therefore, closed-loop control of the mover's stroke is a crucial condition for ensuring the safe operation of the system. On the other hand, linear oscillating motors have specific mechanical resonant frequencies; when the drive frequency matches the mechanical resonant frequency, the system can achieve higher operating efficiency. Therefore, stroke control and resonant operation control need to be implemented collaboratively.

[0004] To reduce system costs and improve long-term operational reliability, sensorless control has become an important research direction in the control of linear oscillating motors. Traditional methods typically estimate the back electromotive force based on the voltage equation and obtain displacement information through integration. However, such methods are susceptible to parameter errors, measurement noise, and DC bias, and the integration stage is prone to introducing integral drift and phase lag.

[0005] Linear oscillating motors belong to single-phase AC drive systems, and their original electrical quantities do not possess the inherent orthogonal winding structure of three-phase motors. To establish a current component control model in a rotating coordinate system for this type of system, it is typically necessary to first construct virtual orthogonal components, and then obtain the desired current components through synchronous rotating coordinate transformation. Shaft current component. Due to the electromechanical coupling relationship between current, velocity, and displacement, there is a certain coupling relationship between the resonant state adjustment and the mover stroke control of the linear oscillating motor. Existing control methods still struggle to balance high-efficiency resonant operation, stroke control accuracy, and dynamic response speed.

[0006] Model predictive current control (MMDC) offers advantages such as fast dynamic response, intuitive control structure, and ease of constraint handling, making it suitable for improving the transient regulation capability of the inner current loop in linear oscillating motors. However, the prediction accuracy of MMDC depends on the accuracy of the motor model parameters. In actual operation, stator resistance may change with temperature rise, and stator inductance may change with magnetic saturation, leading to inconsistencies between the controller's internal model parameters and the actual parameters.

[0007] When parameters such as resistance and inductance are mismatched, the prediction model will produce current prediction errors. These errors may further affect voltage vector selection during delay compensation and rolling optimization processes. Shaft current generates steady-state tracking error. For a displacement-oriented linear oscillating motor control system, Shaft current deviation can affect the resonant operating state. Shaft current deviation can affect stroke control accuracy.

[0008] Existing methods for improving parameter mismatch often employ online parameter identification, model parameter correction, or model-free control. However, these methods are relatively complex to implement and may not be suitable for single-phase reciprocating motion drive systems of linear oscillating motors. Therefore, a robust control method is needed that can suppress steady-state current deviations caused by parameter mismatch and maintain the fast dynamic response characteristics of model predictive current control without directly identifying or correcting model parameters. Summary of the Invention

[0009] To address the shortcomings of the prior art, this invention provides a robust predictive current control method and system for linear oscillating motors, which can suppress steady-state current deviations caused by parameter mismatch and maintain the fast dynamic response characteristics of model predictive current control without directly identifying or correcting model parameters.

[0010] The technical effects to be achieved by this invention are realized through the following technical aspects: In a first aspect, the present invention provides a robust predictive current control method for a linear oscillating motor, comprising the following steps: Collect single-phase electrical quantities of a linear oscillating motor and construct virtual orthogonal components to form a virtual two-phase stationary state. A coordinate system is constructed using Park transformation with synchronized rotation angles. The axis is aligned with the displacement vector of the mover and rotates synchronously. The coordinate system rotates synchronously in the displacement orientation. Obtained in coordinate system Axis current components, Axial current components and their original reference values; set up The shaft current reference value is zero, and it is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value; A discrete current prediction model is established for model predictive current control, and future time-to-time predictions are made based on the discrete current prediction model. shaft current; calculate The current tracking error between the actual shaft current value and the original reference value is calculated by integrating and compensating for the current tracking error to generate... Axis integral compensation and Axis integral compensation amount, and the said Axis integral compensation amount and the The axis integral compensation values ​​are respectively superimposed on the corresponding original reference values ​​to obtain... Shaft virtual reference current and Shaft virtual reference current; As stated The virtual reference current of the axis and the The virtual reference current of the axis is used as the tracking target of the model predictive current control. A cost function is constructed and the inverter output voltage vector and voltage vector action time are optimized to generate a PWM drive signal to suppress the steady-state current deviation caused by model parameter mismatch.

[0011] In some implementations, the method involves acquiring single-phase electrical quantities of a linear oscillating motor and constructing virtual orthogonal components to form a virtual two-phase stationary state. In the coordinate system, construct virtual orthogonal components to form a virtual two-phase stationary state. The coordinate system specifically includes: The single-phase current, voltage, or back EMF signal of the linear oscillating motor is used as... The axis components are obtained through an orthogonal signal generation unit and are related to the... The axial components are orthogonal Axial components, thus forming a virtual two-phase stationary state. Spatial vectors in a coordinate system.

[0012] In some implementations, the aforementioned setting The shaft current reference value is zero, and it is generated based on the mover stroke control target and the estimated mover displacement amplitude. In the shaft current reference value, the estimated value of the mover displacement amplitude is based on The back electromotive force component of the shaft is obtained by algebraic calculation with the fundamental angular frequency, as follows: ,in, This is an estimate of the mover displacement amplitude. Let be the q-axis back electromotive force component. This is the electromagnetic thrust coefficient. ω is the fundamental angular frequency.

[0013] In some implementations, the discrete current prediction model includes one-step calculation delay compensation, so as to State quantity prediction obtained from sampling Current at any moment, and then with Predicting the current at each moment as the initial state prediction Current at any given moment.

[0014] In some implementations, the aforementioned calculation The current tracking error between the actual shaft current value and the original reference value is compensated by integration. The calculation of the integration compensation is as follows: ; ; Among them, the and stated They are respectively Axis integral compensation and The axis integral compensation amount, the and stated They are respectively Axis integral gain and Axis integral gain, the and stated For the corresponding original reference value, the and stated They are respectively Actual value of shaft current and Actual value of shaft current.

[0015] In some implementations, the Shaft virtual reference current and The calculations for the virtual reference current of the shaft are as follows: ; ; in, for The virtual reference current of the axis, for Virtual reference current for axis.

[0016] In some implementations, the aforementioned The virtual reference current of the axis and the The virtual reference current of the shaft is used as the tracking target for the model's predicted current control. A cost function is constructed and the inverter output voltage vector and voltage vector application time are optimized, specifically including: A two-vector model predictive current control is employed, which combines the application of an effective voltage vector and a zero voltage vector within one control cycle, based on a cost function: , Solve for the optimal duty cycle, wherein, the and stated For the predicted time Axis current.

[0017] In some implementations, the solution for the optimal duty cycle specifically includes: The optimal duty cycle and corresponding substitution value are calculated for the forward effective voltage vector and the reverse effective voltage vector of the single-phase full-bridge inverter, respectively, and the set with the smaller substitution value is selected as the output of the current control cycle.

[0018] In a second aspect, the present invention provides a system for implementing the robust predictive current control method for a linear oscillating motor as described in any of the preceding claims, comprising: The displacement orientation state acquisition module is used to construct virtual orthogonal components from the single-phase electrical quantities of the linear oscillating motor, forming a virtual two-phase stationary state. A coordinate system is established, and a Park transformation is performed using a synchronous rotation angle to obtain a displacement-oriented synchronous rotation. coordinate system Axis current components, Axial current components and their original reference values; The outer loop controller is used to set the travel distance. The shaft current reference value is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value; The integral compensation module is used for calculation. The current tracking error between the actual value of the shaft current and the original reference value is integrated and compensated to generate an integral compensation amount and reconstruct the virtual reference current. The model predictive current control module is used to take the virtual reference current as a tracking target, optimize the inverter output voltage vector and voltage vector duration according to the discrete current prediction model, and output a PWM drive signal; and The PWM generation module and single-phase inverter are used to drive a linear oscillating motor according to the PWM drive signal.

[0019] In some implementations, the integral compensation module is located on the reference current input side of the model predictive current control module, and the integral compensation module does not change the predictive model structure and model parameters of the model predictive current control module.

[0020] In summary, the present invention has at least the following advantages: (1) This invention reconstructs the virtual reference current through integral compensation, which can suppress the steady-state current tracking deviation caused by the mismatch of resistance and inductance parameters without directly identifying or correcting the motor model parameters. The engineering implementation is relatively simple. (2) The present invention maintains the displacement orientation control framework. The shaft current is close to the resonant operating reference value, which helps to keep the system operating near the mechanical resonance point under parameter mismatch conditions, while also... Shaft current regulation enables closed-loop control of the mover stroke; (3) The present invention sets the integral compensation on the reference current side without changing the basic prediction model and model parameters of the model predictive current controller, which can improve the steady-state robustness while maintaining a fast dynamic response. (4) The present invention can combine dual vector modulation and optimal duty cycle solution to achieve smooth current tracking under fixed switching frequency and reduce steady-state current ripple. Attached Figure Description

[0021] Figure 1 A flowchart of the method provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the phasor relationship of the linear oscillating motor electromechanical system provided in Embodiment 1 of the present invention; Figure 3 The virtual two-phase static provided in Embodiment 1 of the present invention A schematic diagram of spatial vector relationships in a coordinate system; Figure 4 The displacement-oriented synchronous rotation provided in Embodiment 1 of the present invention Schematic diagram of spatial vector relationships in the coordinate system; Figure 5 This is a control effect diagram of the method of the present invention under parameter mismatch conditions provided in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the displacement orientation state acquisition module provided in Embodiment 2 of the present invention; Figure 7 This is a block diagram of the control principle of the model prediction current control module provided in Embodiment 2 of the present invention; Figure 8 This is an overall structural block diagram of the system provided in Embodiment 2 of the present invention; Detailed Implementation To facilitate understanding of the present invention, a more comprehensive description will be given below in conjunction with the accompanying drawings and specific embodiments. The drawings illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not 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. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] Example 1: Please see Figures 1-4 This invention provides a robust predictive current control method for linear oscillating motors, applicable to reciprocating motion drives such as linear compressors and Stirling refrigerators, and particularly suitable for high-precision mover stroke control and resonant frequency tracking under conditions of model parameter deviations such as resistance and inductance.

[0026] This embodiment uses a 120 W rated power moving magnet linear oscillating motor as the object, driven by a single-phase full-bridge inverter, with a DC bus voltage of 130 V. The controller can be implemented using a microprocessor or a digital signal processor. The controller collects stator voltage and stator current, and performs state observation, coordinate transformation, integral compensation, and model predictive current control within a fixed sampling period.

[0027] A robust predictive current control method for a linear oscillating motor includes the following steps: S100: Collect single-phase electrical quantities of the linear oscillating motor and construct virtual orthogonal components to form a virtual two-phase stationary state. A coordinate system is constructed using Park transformation with synchronized rotation angles. The axis is aligned with the displacement vector of the mover and rotates synchronously. The coordinate system rotates synchronously in the displacement orientation. Obtained in coordinate system Axis current components, Axial current components and their original reference values.

[0028] First, an electrical and mechanical coupling model of the linear oscillating motor is established. The stator voltage equation can be expressed as: , The equation of motion for a machine can be expressed as: , Back electromotive force satisfies ,in Stator voltage, For stator current, It is the back electromotive force. For the displacement of the mover. For the motioner velocity, For stator resistance, For stator inductance, For the equivalent mass of the mover, For equivalent damping, For equivalent stiffness, This is the electromagnetic thrust coefficient.

[0029] Under sinusoidal steady state, the mover displacement and current can be expressed as phasors of the same frequency. and The mechanical equation can be written as: , in, For the operating angular frequency, The imaginary unit. When At that time, the elastic term and the inertial term cancel each other out, that is... The system is in a mechanical resonance operating state. At this time, the electromagnetic thrust is mainly used to compensate for damping losses, and there is approximately a relationship between the stator current and the mover displacement. Phase relationship.

[0030] Based on the 90° phase relationship between the stator current and the mover displacement under this resonant condition, single-phase electrical quantities of the linear oscillating motor are collected, and virtual orthogonal components are constructed to form a virtual two-phase stationary state. Coordinate system.

[0031] Regarding the construction of a virtual two-phase static In this coordinate system, because the linear oscillating motor is a single-phase AC drive system, the collected current, voltage, and back electromotive force are all single-phase AC quantities, lacking a naturally two-phase orthogonal structure. This embodiment uses the original single-phase signal as... Axis components are obtained through a second-order generalized integrator or other orthogonal signal generation units. Orthogonal components of the axes are used to expand single-phase electrical quantities into virtual spatial vectors. For any AC quantity , can be represented as , , ,in This indicates the operation of generating orthogonal signals.

[0032] Constructing displacement-oriented synchronous rotation In coordinate system, according to the synchronous rotation angle For virtual two-phase static Perform the Park transformation on the spatial vector in the coordinate system to obtain shaft and Shaft current component, synchronous rotation angle It can be obtained through orthogonal decomposition of the back electromotive force estimate and phase-locked loop, or it can be updated by combining the fundamental angular frequency output by the frequency-locked loop. Based on the above transformation, displacement-oriented synchronous rotation can be obtained. Current state equation and mechanical equation in coordinate system: , , in , They are respectively current and displacement, rotating synchronously in the displacement orientation. Spatial vectors in a coordinate system Represents the system damping coefficient. represent shaft current, represent Axis current.

[0033] Under displacement orientation conditions, let The axis and the displacement vector of the mover coincide in direction. Because in simple harmonic motion, the phase of the mover's velocity leads the phase of its displacement. Furthermore, the back electromotive force is proportional to the velocity of the mover, therefore when When the shaft and the displacement vector of the mover are aligned, the back electromotive force vector is located at axial direction, satisfying , The controller adjusts the synchronous rotation angle to generate back electromotive force. The axial components converge to zero, thereby achieving displacement orientation.

[0034] S200, Settings The shaft current reference value is zero, and it is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value.

[0035] Specifically, the estimated value of the mover displacement amplitude is based on The back electromotive force component of the shaft is obtained by algebraic calculation with the fundamental angular frequency, as follows: ,in, This is an estimate of the mover displacement amplitude. Let be the q-axis back electromotive force component. This is the electromagnetic thrust coefficient. Given the fundamental angular frequency, this calculation method does not require pure integration of the back electromotive force.

[0036] Synchronous rotation in the above displacement orientation In coordinate system, The shaft current component and the mover displacement amplitude can be expressed as: , Therefore, The shaft current component reflects the degree to which the system deviates from its mechanical resonance state. When hour, ,thus As the value approaches zero, the system approaches mechanical resonance operation. The shaft current component is related to the amplitude of the mover displacement and is adjusted by the outer loop controller. Shaft current reference value It can realize closed-loop control of the actuator stroke.

[0037] Furthermore, a displacement orientation control framework is used to establish The correspondence between shaft current components and the resonant state and mover stroke amplitude of a linear oscillating motor. The axis current component is used to characterize the degree to which the system deviates from its resonant state. The shaft current component is used to adjust the mover stroke amplitude. The integral compensation mechanism of this invention does not change the displacement orientation control framework and motor prediction model parameters, but rather adjusts the parameters on the reference current input side. The shaft current reference value is corrected online.

[0038] S300. Establish a discrete current prediction model for model predictive current control, and predict future times based on the discrete current prediction model. Axis current.

[0039] Specifically, according to Time-of-sampling Axis current, voltage vector, fundamental angular frequency, and back electromotive force component are used to predict... The current state at a given moment; further... The predicted value at time is the initial state, and the prediction is... At any given moment, under the action of the candidate voltage vector Shaft current. This prediction model can be derived from continuous time... The axis current equation is obtained using forward Euler discretization. Specifically, this is achieved by combining the displacement orientation condition and... The state equation for continuous current in the coordinate system, discretized using the forward Euler method, yields: Current prediction model at time: , in, The sampling period is , for Moment axis, shaft current, , for Moment axis, shaft voltage, for Moment The back electromotive force component of the shaft, The operating angular frequency.

[0040] Considering the one-step control delay caused by digital controller sampling, calculation, and PWM update, Predicting the current at each moment as the initial state, and further predicting... Current at any moment: , Within one control cycle, the change in back electromotive force can be approximated as small, i.e. The above. The predicted current at each moment is used for subsequent cost function calculation and voltage vector action time optimization.

[0041] When the actual resistance or inductance differs from the parameters in the controller's internal model, a deviation will occur between the predicted current and the actual current. This deviation will affect the cost function's selection of the voltage vector and duty cycle, thereby... The shaft current exhibits a steady-state deviation. The steady-state deviation of the shaft current will weaken the system's ability to maintain resonant operation. Steady-state deviation of shaft current can reduce the accuracy of mover stroke control. To mitigate this problem, this embodiment introduces integral compensation calculation.

[0042] S400, Calculation The current tracking error between the actual shaft current value and the original reference value is calculated by integrating and compensating for the current tracking error to generate... Axis integral compensation and Axis integral compensation amount, and the said Axis integral compensation amount and the The axis integral compensation values ​​are respectively superimposed on the corresponding original reference values ​​to obtain... Shaft virtual reference current and Virtual reference current for axis.

[0043] calculate Shaft current error as well as Shaft current error and in accordance with: , , Update the integral compensation amount. As needed, the integral compensation amount can be limited, separated, discharged, or subjected to anti-saturation treatment to reduce excessive integration during the dynamic process.

[0044] Subsequently, the integral compensation is superimposed on the original reference current to obtain the virtual reference current: , .

[0045] The integral compensation mechanism changes the optimization objective of predictive control by reconstructing the reference current, without directly modifying the motor model parameters.

[0046] S500, as described The virtual reference current of the axis and the The virtual reference current of the axis is used as the tracking target of the model predictive current control. A cost function is constructed and the inverter output voltage vector and voltage vector action time are optimized to generate a PWM drive signal to suppress the steady-state current deviation caused by model parameter mismatch.

[0047] In the model-predictive current control loop, a dual-vector modulation strategy is employed. For a single-phase full-bridge inverter, a combination of an effective voltage vector and a zero voltage vector is applied within one control cycle. Since the predicted current can be expressed as a linear function of the duty cycle, a cost function can be established: , The optimal duty cycle is obtained by setting the partial derivative of the cost function with respect to the duty cycle to zero. The cost value is calculated for both the forward and reverse effective voltage vectors, and the one with the smaller cost value is selected as the output for the current control cycle.

[0048] Through the above control process, when parameter mismatch causes steady-state current deviation, the integral compensation quantity will adaptively adjust the virtual reference current according to the error direction, so that the actual current deviation is correct. The shaft current gradually approaches the original control target. Therefore, it is possible to maintain [the desired control] under conditions of parameter uncertainty. The shaft current approaches the resonant operating reference value and passes through The shaft current maintains the accuracy of the mover stroke tracking.

[0049] Example 2: This embodiment provides a system based on Embodiment 1. Figures 1-4 Based on reference Figures 5-8 .

[0050] like Figure 5 As shown, represent shaft current, represent shaft current, represent Shaft current reference value, represent Under the conditions of shaft current reference value and parameter mismatch, the robust predictive current control method for linear oscillating motor provided by this invention can enable... The shaft current gradually approaches its reference value, and makes... The shaft current tracks the reference value generated by the outer loop of the stroke. This demonstrates that when the motor model parameters differ from the actual parameters, reconstructing the virtual reference current through integral compensation can suppress steady-state current deviations caused by model parameter mismatch, while maintaining the resonant operating state and mover stroke control accuracy of the linear oscillating motor.

[0051] like Figure 6 As shown, the displacement orientation state acquisition module includes a second-order generalized integrator-frequency-locked loop (SOGI-FLL), a sliding mode observer, and a second-order generalized integrator-phase-locked loop (SOGI-PLL). The second-order generalized integrator-frequency-locked loop is used to extract the fundamental frequency from the stator current. The sliding mode observer is used to obtain the back electromotive force estimate based on the stator voltage and stator current. The second-order generalized integrator-phase-locked loop is used to obtain the back electromotive force estimate based on the back electromotive force estimate. The shaft current component adjusts the synchronous rotation angle to make the back electromotive force estimate... The shaft current component converges to zero, thus achieving displacement-oriented synchronous rotation. Coordinate system.

[0052] like Figure 7 As shown, the input side of the model predictive current control module is equipped with an integral compensation circuit. The integral compensation circuit is based on... Actual value of shaft current and Error between the original reference values ​​of the shaft Actual value of shaft current and Error generation between the original reference values ​​of the shaft Axis integral compensation and The axis integral compensation amount is calculated, and the integral compensation amount is superimposed on the corresponding original reference value to obtain... Shaft virtual reference current and A virtual reference current is used as the axis. The model predictive current control module uses this virtual reference current as the tracking target to evaluate the cost function and calculate the duty cycle, thereby suppressing steady-state current deviation without changing the prediction model parameters.

[0053] like Figure 8As shown, the system as a whole includes a displacement orientation state acquisition module, a stroke outer loop controller, an integral compensation module, a model prediction current control module, a PWM generation module, a single-phase inverter, and a linear oscillating motor. The displacement orientation state acquisition module is used to obtain the operating frequency, synchronous rotation angle, and displacement orientation. Current components in the coordinate system; the outer loop controller is used to generate based on the given and estimated values ​​of the mover displacement amplitude. Shaft original reference current; integral compensation module used for reconstruction A virtual reference current for the shaft; a model predictive current control module is used to determine the optimal voltage vector combination and its application time based on the virtual reference current; a PWM generation module and a single-phase inverter drive the linear oscillating motor to run according to the control quantity.

[0054] A system for implementing the robust predictive current control method for a linear oscillating motor of Embodiment 1, comprising: The displacement orientation state acquisition module is used to construct virtual orthogonal components from the single-phase electrical quantities of the linear oscillating motor, forming a virtual two-phase stationary state. A coordinate system is established, and a Park transformation is performed using a synchronous rotation angle to obtain a displacement-oriented synchronous rotation. coordinate system Axis current components, Axial current components and their original reference values; The outer loop controller is used to set the travel distance. The shaft current reference value is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value; The integral compensation module is used for calculation. The current tracking error between the actual value of the shaft current and the original reference value is integrated and compensated to generate an integral compensation amount and reconstruct the virtual reference current. The model predictive current control module is used to take the virtual reference current as a tracking target, optimize the inverter output voltage vector and voltage vector duration according to the discrete current prediction model, and output a PWM drive signal; and The PWM generation module and single-phase inverter are used to drive a linear oscillating motor according to the PWM drive signal.

[0055] Among them, the model predictive current control module is a dual-vector model predictive current control module, which applies a combination of an effective voltage vector and a zero voltage vector in each fixed control cycle to achieve fixed switching frequency operation and reduce steady-state current ripple.

[0056] Example 3: The difference between this embodiment and Embodiment 1 is that this embodiment further optimizes the structure of the present invention. For similarities, please refer to Embodiment 2.

[0057] In this embodiment, the integral compensation module is set on the reference current input side of the model predictive current control module. The integral compensation module does not change the prediction model structure and model parameters of the model predictive current control module.

[0058] The above description is merely an example and illustration of the structure of this invention, and while the description is specific and detailed, it should not be construed as limiting the scope of this invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this invention, and these obvious substitutions all fall within the protection scope of this invention.

Claims

1. A robust predictive current control method for a linear oscillating motor, characterized in that, Includes the following steps: Collect single-phase electrical quantities of a linear oscillating motor and construct virtual orthogonal components to form a virtual two-phase stationary state. A coordinate system is constructed using Park transformation with synchronized rotation angles. The axis is aligned with the displacement vector of the mover and rotates synchronously. The coordinate system rotates synchronously in the displacement orientation. Obtained in coordinate system Axis current components, Axial current components and their original reference values; set up The shaft current reference value is zero, and it is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value; A discrete current prediction model is established for model predictive current control, and future time-to-time predictions are made based on the discrete current prediction model. shaft current; calculate The current tracking error between the actual shaft current value and the original reference value is calculated by integrating and compensating for the current tracking error to generate... Axis integral compensation and axis integral compensation amount, and the said Axis integral compensation amount and the The axis integral compensation values ​​are respectively superimposed on the corresponding original reference values ​​to obtain... Shaft virtual reference current and Shaft virtual reference current; As stated The virtual reference current of the shaft and the The virtual reference current of the axis is used as the tracking target of the model predictive current control. A cost function is constructed and the inverter output voltage vector and voltage vector action time are optimized to generate a PWM drive signal to suppress the steady-state current deviation caused by model parameter mismatch.

2. The robust predictive current control method for a linear oscillating motor according to claim 1, characterized in that, The method described above involves collecting single-phase electrical quantities of a linear oscillating motor and constructing virtual orthogonal components to form a virtual two-phase stationary state. In the coordinate system, construct virtual orthogonal components to form a virtual two-phase stationary state. The coordinate system specifically includes: The single-phase current, voltage, or back EMF signal of the linear oscillating motor is used as... The axis components are obtained through an orthogonal signal generation unit and are related to the... The axial components are orthogonal Axial components, thus forming a virtual two-phase stationary state. Spatial vectors in a coordinate system.

3. The robust predictive current control method for a linear oscillating motor according to claim 1, characterized in that, The aforementioned settings The shaft current reference value is zero, and it is generated based on the mover stroke control target and the estimated mover displacement amplitude. In the shaft current reference value, the estimated value of the mover displacement amplitude is based on The back electromotive force component of the shaft is obtained by algebraic calculation with the fundamental angular frequency, as follows: ,in, This is an estimate of the mover displacement amplitude. Let be the q-axis back electromotive force component. This is the electromagnetic thrust coefficient. ω is the fundamental angular frequency.

4. The robust predictive current control method for a linear oscillating motor according to claim 1, characterized in that, The discrete current prediction model includes one-step calculation delay compensation, so as to... State quantity prediction obtained from sampling Current at any moment, and then with Predicting the current at each moment as the initial state prediction Current at any given moment.

5. The robust predictive current control method for a linear oscillating motor according to claim 4, characterized in that, The calculation The current tracking error between the actual shaft current value and the original reference value is compensated by integration. The calculation of the integration compensation is as follows: ； ； Among them, the and stated They are respectively Axis integral compensation and The axis integral compensation amount, the and stated They are respectively Axis integral gain and Axis integral gain, the and stated For the corresponding original reference value, the and stated They are respectively Actual value of shaft current and Actual value of shaft current.

6. The robust predictive current control method for a linear oscillating motor according to claim 5, characterized in that, The Shaft virtual reference current and The calculations for the virtual reference current of the shaft are as follows: ； ； in, for The virtual reference current of the axis, for Virtual reference current for axis.

7. The robust predictive current control method for a linear oscillating motor according to claim 4, characterized in that, The above-mentioned The virtual reference current of the shaft and the The virtual reference current of the shaft is used as the tracking target for the model's predicted current control. A cost function is constructed and the inverter output voltage vector and voltage vector application time are optimized, specifically including: A two-vector model predictive current control is employed, which combines the application of an effective voltage vector and a zero voltage vector within one control cycle, based on a cost function: ， Solve for the optimal duty cycle, wherein, the and stated For the predicted time Axis current.

8. The robust predictive current control method for a linear oscillating motor according to claim 7, characterized in that, The aforementioned solution for the optimal duty cycle specifically includes: The optimal duty cycle and corresponding substitution value are calculated for the forward effective voltage vector and the reverse effective voltage vector of the single-phase full-bridge inverter, respectively, and the set with the smaller substitution value is selected as the output of the current control cycle.

9. A system, characterized in that, The robust predictive current control method for the linear oscillating motor according to any one of claims 1-8 includes: The displacement orientation state acquisition module is used to construct virtual orthogonal components from the single-phase electrical quantities of the linear oscillating motor, forming a virtual two-phase stationary state. A coordinate system is established, and a Park transformation is performed using a synchronous rotation angle to obtain a displacement-oriented synchronous rotation. coordinate system Axis current components, Axial current components and their original reference values; The outer loop controller is used to set the travel distance. The shaft current reference value is generated based on the mover stroke control target and the estimated mover displacement amplitude. Shaft current reference value; The integral compensation module is used for calculation. The current tracking error between the actual value of the shaft current and the original reference value is integrated and compensated to generate an integral compensation amount and reconstruct the virtual reference current. The model predictive current control module is used to take the virtual reference current as a tracking target, optimize the inverter output voltage vector and voltage vector duration according to the discrete current prediction model, and output a PWM drive signal; and The PWM generation module and single-phase inverter are used to drive a linear oscillating motor according to the PWM drive signal.

10. The system according to claim 9, characterized in that, The integral compensation module is located on the reference current input side of the model prediction current control module. The integral compensation module does not change the prediction model structure and model parameters of the model prediction current control module.

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