A deadbeat predictive control method

Abstract

The present invention relates to the field of motor control technology, and specifically provides a deadbeat predictive control method. Aiming at the non-periodic and periodic disturbances existing in the current loop of a permanent magnet synchronous motor, a finite time super-helical expansion state observer is designed in combination with finite time theory and super-helical theory on the basis of a traditional deadbeat predictive control method, and the observer is used to estimate and compensate for non-periodic disturbances such as cross-coupling disturbances, parameter perturbations and external disturbances existing in the current loop more quickly and accurately within a finite time; at the same time, a vector resonance controller is designed to estimate and compensate for periodic disturbances such as flux harmonics and voltage harmonics in the current loop. The present invention can not only estimate and compensate for non-periodic disturbances more quickly, but also estimate and compensate for periodic disturbances efficiently, effectively improving the dynamic response and robustness of the current control of the permanent magnet synchronous motor.

Description

Technical Field

[0001] The invention relates to the technical field of motor control, and in particular provides a deadbeat predictive control method based on a finite-time super-helical expansion state observer. Background Art

[0002] Permanent magnet synchronous motor (PMSM) is widely used in electric vehicles, CNC machine tools, robot servo control and other fields due to its advantages such as high efficiency, high power density, high precision and easy maintenance. However, there are various disturbances in the actual application of permanent magnet synchronous motor system. Non-periodic disturbances such as cross-coupling disturbances, parameter perturbations and external disturbances in the current loop reduce the stability of the system, and periodic disturbances such as flux harmonics and voltage harmonics reduce the control accuracy of the system. At present, the widely used control strategies for non-periodic disturbances in permanent magnet synchronous motors include anti-disturbance control, predictive control, robust control and sliding mode control.

[0003] In recent years, the deadbeat predictive control method has received extensive attention in the field of permanent magnet synchronous motor control, and a hyperlocal model is introduced to suppress the influence of parameter perturbations. In order to accurately and timely estimate the total disturbance, a fast-converging and high-precision state observer is required, which requires the extended state observer to have a high-gain form. However, the high-gain extended state observer is very sensitive to measurement noise, which will be amplified by the high-gain extended state observer and then applied to the system, which will cause system vibration or even instability. Therefore, the fast and accurate estimation of disturbances and the suppression of measurement noise are an inevitable contradiction for the extended state observer.

[0004] Therefore, there is an urgent need for a current control strategy that can provide appropriate disturbance estimation accuracy and high-precision control of the current. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a beat-free predictive control method based on a finite-time superhelical expanded state observer, which uses the finite-time convergence theory and the superhelical theory to quickly estimate non-periodic disturbances such as cross-coupling disturbances, parameter perturbations and external disturbances in the compensation current loop, and uses the vector resonance control theory to estimate periodic disturbances such as flux harmonics and voltage harmonics in the compensation current loop, thereby achieving strong robustness and high-precision current control of the permanent magnet synchronous motor.

[0006] The deadbeat predictive control method provided by the present invention comprises:

[0007] Establish the dq axis current equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system, discretize it to obtain the discrete current equation, and obtain the predicted voltage equation based on the discrete current equation;

[0008] According to the predicted voltage equation and the current loop disturbance of the permanent magnet synchronous motor, a deadbeat predictive control model based on the hyperlocal model is established.

[0009] An extended state observation model of the dq axis current equation of the permanent magnet synchronous motor is established, and a finite time super helical extended state observer is designed based on finite time theory and super helical control theory.

[0010] The control rate of the permanent magnet synchronous motor current loop is designed based on the zero-beat predictive control model and the finite-time super-helical expanded state observer; and a vector resonant controller is designed in the current loop control to obtain the final current loop controller.

[0011] Preferably, the dq axis current equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system is:

[0012] ;

[0013] in, represents the stator current of the d-axis, represents the stator current of the q axis, represents the stator voltage of the d-axis, represents the stator voltage of the q-axis, represents the stator inductance of the d-axis, represents the stator inductance of the q-axis, is the stator resistance, is the electrical angular velocity, is the rotor flux.

[0014] Preferably, the dq axis current equation is subjected to first-order forward differentiation to obtain a discrete current equation:

[0015] ;

[0016] Among them, k represents any time;

[0017] Then the predicted voltage equation at time k is:

[0018] ;

[0019] in, represents the sampling period, express The reference current value of the d-axis at the moment, express The reference current value of the q axis at the moment;

[0020] To compensate for the delay of electronic components, equation (3) is rewritten as:

[0021] ;

[0022] make , , , then the final predicted voltage equation is obtained from equation (4):

[0023] .

[0024] Preferably, the current loop disturbance includes non-periodic disturbance and periodic disturbance, and the expressions of the non-periodic disturbance of the d-axis and q-axis of the permanent magnet synchronous motor are respectively:

[0025] ;

[0026] ;

[0027] in, represents the non-periodic perturbation of the d-axis, represents the non-periodic disturbance of the q-axis, represents the cross-coupled perturbation of the d-axis, represents the cross-coupled disturbance of the q-axis, represents the known perturbation of the d-axis, represents a known disturbance on the q-axis, represents the disturbance of the d-axis caused by parameter perturbation, represents the disturbance of the q-axis caused by parameter perturbation, represents the external uncertain disturbance of the d-axis, represents the external uncertain disturbance of the q-axis, , is the nominal value of the d-axis stator inductance, is the nominal value of the q-axis stator inductance, is the nominal value of the stator inductance of the permanent magnet synchronous motor, is the nominal value of the stator resistance of the permanent magnet synchronous motor, , , .

[0028] Preferably, the expressions of the periodic disturbances of the d-axis and q-axis of the permanent magnet synchronous motor are:

[0029] ;

[0030] in, represents the periodic perturbation of the d-axis, represents the periodic disturbance of the q-axis, represents the flux harmonic of the d-axis, represents the flux harmonic of the q-axis, represents the voltage harmonics of the d-axis, Indicates the voltage harmonics of the q-axis.

[0031] Preferably, the deadbeat predictive control model obtained according to the predicted voltage equation of formula (5) and the current loop disturbance is:

[0032] ;

[0033] in, represents the current loop disturbance of the d-axis, represents the current loop disturbance of the q-axis, To control the gain, represents the d-axis voltage reference value at time k+1, Represents the q-axis voltage reference value at time k+1.

[0034] Preferably, the process of establishing the extended state observation model of the dq axis current equation of the permanent magnet synchronous motor is as follows:

[0035] Pick , , , , the expanded state observation model of the dq axis current equation is obtained as:

[0036] ;

[0037] in, , , , , .

[0038] Preferably, the finite-time superhelical expansion state observer is designed as:

[0039] ;

[0040] in, , represents the estimated value of the state vector, and is the error correction term, , and is the observer gain value, , , , are observer parameters.

[0041] Preferably, the control rate of the current loop is designed as:

[0042] .

[0043] Preferably, the transfer function of the vector resonant controller is for:

[0044] ;

[0045] in, and is the resonant gain, is the damping frequency, is the resonant frequency, and , ;

[0046] The transfer function of the vector resonant controller is After discretization, the discretized transfer function is:

[0047] ;

[0048] in, ;

[0049] And add the discretized transfer function to the current loop control, and the final current loop controller is:

[0050] .

[0051] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0052] The invention designs an extended state observer based on the finite time convergence theory and the superhelix theory. By improving the superhelix term to replace the linear estimation error term of the traditional extended state observer, the rapidity and accuracy of the extended state observer are significantly improved. The finite time superhelix extended state observer can estimate and compensate for non-periodic disturbances such as cross-coupling disturbances, parameter perturbations and external disturbances in the current loop more quickly and accurately within a finite time, thereby enhancing the dynamic response speed and robustness of the system. In addition, for periodic disturbances such as flux harmonics and voltage harmonics in the current loop, a vector resonant controller is added to the current loop controller to suppress them, thereby further improving the performance of the control system. The invention realizes the estimation and compensation of non-periodic disturbances and periodic disturbances in the current loop by combining the finite time superhelix extended state observer and the vector resonant controller. Compared with the traditional deadbeat predictive control method, the invention has the advantages of high disturbance estimation accuracy, insensitivity to parameter changes, strong system adaptability, good dynamic performance, good robustness, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a control structure diagram of a deadbeat predictive control method provided by an embodiment of the present invention;

[0054] Figure 2 is a structural diagram of a simulation model of a permanent magnet synchronous motor servo control system provided according to an embodiment of the present invention;

[0055] Figure 3 (a) is a d-axis current curve;

[0056] FIG3( b ) is a d-axis current curve diagram using the method of the present invention;

[0057] FIG4 (a) is a q-axis current curve diagram using the traditional deadbeat predictive control method;

[0058] FIG4( b ) is a q-axis current curve diagram using the method of the present invention;

[0059] Figure 5 (a) is the Fourier analysis result of the q-axis current using the traditional deadbeat predictive control method;

[0060] FIG5( b ) is the Fourier analysis result of the q-axis current using the method of the present invention;

[0061] FIG6 (a) is a graph showing the a-phase current curve using the conventional deadbeat predictive control method;

[0062] FIG6( b ) is a graph showing the a-phase current curve using the method of the present invention.

[0063] FIG7 (a) is a q-axis reference current curve diagram of the conventional deadbeat predictive control method when the inductor L is mismatched;

[0064] FIG7( b ) is a q-axis reference current curve diagram using the method of the present invention when the inductance L is mismatched;

[0065] FIG7 (c) is a graph showing the actual current curve of the q-axis when the inductance L is mismatched and the conventional deadbeat predictive control method is used;

[0066] FIG. 7( d ) is a graph showing the actual current curve of the q-axis using the method of the present invention. DETAILED DESCRIPTION

[0067] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0068] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0069] Please see Figure 1In order to solve the non-periodic disturbance and periodic disturbance existing in the current loop of the permanent magnet synchronous motor, the embodiment of the present invention provides a deadbeat predictive control method based on a finite time super-helical extended state observer. The linear term in the traditional extended state observer is improved based on the finite time theory and super-helical control theory to achieve higher tracking accuracy and faster tracking speed. The specific design steps are as follows:

[0070] S1: First, establish the current equation of the permanent magnet synchronous motor. You can refer to the general method for design or improve it according to actual needs. Specifically, in practical applications, in order to simplify the model and improve the calculation efficiency, ignore the non-main influencing factors such as hysteresis loss, eddy current and core saturation of the surface-mounted permanent magnet synchronous motor, and then obtain the dq axis current equation in the synchronous rotating coordinate system, which can be expressed as:

[0071] ;

[0072] in, represents the stator current of the permanent magnet synchronous motor d-axis, represents the stator current of the q axis, represents the stator voltage of the d-axis, represents the stator voltage of the q-axis, represents the stator inductance of the d-axis, represents the stator inductance of the q-axis, is the stator resistance of the permanent magnet synchronous motor, is the electrical angular velocity, is the rotor flux.

[0073] Since equation (1) is a continuous-time dq-axis current equation, it needs to be discretized in practical applications to obtain a current equation in discrete-time form. The discretization process is: perform first-order forward difference discretization on the dq-axis current equation of equation (1) to obtain the discrete current equation:

[0074] ;

[0075] Here, k represents any time.

[0076] In the control strategy, it is necessary to predict the voltage at the next moment in order to calculate the control command in advance. Therefore, the predicted voltage equation at any k moment is obtained by the discrete current equation of formula (2), and its expression is:

[0077] ;

[0078] in, represents the sampling period, express The reference current value of the d-axis at the moment, express The reference current value of the q axis at time.

[0079] Due to the delay effect of electronic components, the predicted voltage equation of equation (3) needs to be compensated for one step of delay to ensure that the control command can be accurately reflected in the dynamic response of the motor. The compensated predicted voltage equation can be rewritten as:

[0080] .

[0081] Since the signal sampling period is very short, it can be considered , , Therefore, after further adjusting the compensated prediction voltage equation of equation (4), the final prediction voltage equation can be obtained as follows:

[0082] .

[0083] S2: Analyze the current loop disturbance of the permanent magnet synchronous motor. The current loop disturbance includes non-periodic disturbance and periodic disturbance. Among them, the non-periodic disturbance mainly includes dq axis cross-coupling disturbance, disturbance caused by parameter perturbation, external uncertain disturbance and known disturbance. Then the non-periodic disturbance of the d-axis and q-axis of the permanent magnet synchronous motor can be expressed as:

[0084] The non-periodic perturbation expression of the d-axis is:

[0085] ;

[0086] The non-periodic perturbation expression of the q-axis is:

[0087] ;

[0088] in, represents the non-periodic perturbation of the d-axis, represents the non-periodic disturbance of the q-axis, represents the cross-coupled perturbation of the d-axis, represents the cross-coupled disturbance of the q-axis, represents the known perturbation of the d-axis, represents a known disturbance on the q-axis, represents the disturbance of the d-axis caused by parameter perturbation, represents the disturbance of the q-axis caused by parameter perturbation, represents the external uncertain disturbance of the d-axis, represents the external uncertain disturbance of the q-axis, , is the nominal value of the d-axis stator inductance, is the nominal value of the q-axis stator inductance, is the nominal value of the stator inductance of the permanent magnet synchronous motor, is the nominal value of the stator resistance of the permanent magnet synchronous motor, , , .

[0089] The periodic disturbances existing in the current loop of the permanent magnet synchronous motor mainly include the flux harmonics caused by the motor processing technology and the voltage harmonics caused by the inverter nonlinearity. The specific analysis process of the flux harmonics and voltage harmonics is as follows:

[0090] Ideally, the theoretical flux distribution of a permanent magnet synchronous motor should be a sinusoidal waveform. However, for an actual permanent magnet synchronous motor system, it is difficult to obtain an ideal sinusoidal flux distribution due to manufacturing tolerances, magnetic saturation, and other non-ideal factors in motor design. This results in harmonics in the actual flux waveform. The periodic disturbances in the current loop are modeled and analyzed, and it is determined that the main orders of the periodic disturbances affecting the current loop are the 6th and 12th harmonics. Therefore, the flux harmonics of the dq axis of the permanent magnet synchronous motor can be expressed as:

[0091] ;

[0092] in, represents the flux harmonic of the d-axis, represents the flux harmonic of the q-axis, represents the amplitude of the 6nth harmonic of the d-axis flux, Represents the amplitude of the 6nth harmonic of the q-axis flux.

[0093] For the IGBT voltage source inverter in the permanent magnet synchronous motor system, in order to avoid the inverter short circuit caused by the upper and lower switch bridge arms being closed at the same time, a certain dead time needs to be set. During the dead time, the output voltage of the inverter cannot change suddenly, which leads to the distortion of the voltage waveform. Therefore, the design of the dead time will inevitably cause voltage harmonics. The voltage harmonics of the dq axis of the permanent magnet synchronous motor are expressed as:

[0094] ;

[0095] in, represents the voltage harmonics of the d-axis, represents the voltage harmonics of the q-axis, is the dead time, is the sampling time of the voltage source inverter, is the DC bus voltage.

[0096] Combining the flux harmonics and voltage harmonics, the d-axis and q-axis periodic disturbances of the permanent magnet synchronous motor are expressed as:

[0097] ;

[0098] in, represents the periodic perturbation of the d-axis, represents the periodic disturbance of the q-axis.

[0099] Furthermore, according to equations (6) and (7) representing the non-periodic disturbances of the d-axis and q-axis and equation (10) representing the periodic disturbance, the current disturbance of the d-axis of the permanent magnet synchronous motor, that is, the sum of the periodic disturbance and the non-periodic disturbance of the d-axis, is: The current disturbance of the q-axis of the permanent magnet synchronous motor, that is, the sum of the periodic disturbance and the non-periodic disturbance of the q-axis is: .

[0100] By introducing the total disturbance of the d-axis and q-axis into equation (5) representing the final predicted voltage equation, the deadbeat predictive control model based on the super-local model can be obtained:

[0101] ;

[0102] in, To control the gain, represents the d-axis voltage reference value at time k+1, Represents the q-axis voltage reference value at time k+1.

[0103] S3: According to the dq axis current equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system, a finite time super-helical expansion state observer is designed. The specific process is as follows:

[0104] Pick , , , , the expanded state observation model of the dq axis current equation is obtained as:

[0105] ;

[0106] in, , , , , , is the state vector, representing the d(q) axis current, Represents the state vector The estimated value of Represents the first derivative of the lumped perturbation about the d(q) axis.

[0107] According to the extended state model (12) of the permanent magnet synchronous motor d(q) axis current equation, the error correction term is innovatively improved based on the finite time theory and super helical control theory, and the finite time super helical extended state observer is designed as:

[0108] ;

[0109] Among them, the superhelical term is used to replace the linear estimation error term in the traditional method, and the improved error correction term is:

[0110] ;

[0111] represents the estimated value of the state vector, and is the error correction term, , and is the observer gain value, , , , are observer parameters.

[0112] When selecting parameters, use and , and by choosing appropriate observer parameters , , , , observe the non-periodic disturbances that appear in the current loop during the operation of the motor. When middle, The term plays a major role in the observation of disturbances and can make the observer converge quickly. When middle, This item plays a major role in the observation of disturbances and can also make the observer converge quickly. At the same time, for different operating conditions, better results can be achieved by adjusting the parameters of the observer.

[0113] According to the pole placement strategy of the finite-time super-helical expansion state observer, the observer gain value can be adjusted according to the following formula: and for:

[0114] ;

[0115] in, is the bandwidth of the finite-time superhelical expansion state observer.

[0116] Compared with the traditional linear / nonlinear extended state observer, the finite-time superhelical extended state observer can better estimate the time-varying disturbance and converge within a finite time.

[0117] Furthermore, according to the extended state observation model of the dq axis current equation and the finite time super-helical extended state observer, the error equation of the permanent magnet synchronous motor system can be obtained as follows:

[0118] .

[0119] in, and Indicates state error.

[0120] After the finite-time superhelical expansion state observer is designed, its stability needs to be judged. A condition for the finite-time stability of the dynamic system is provided. If there is a positive definite matrix that satisfies specific conditions, it is considered that the state of the system can be stable in a finite time. The specific process is as follows:

[0121] Lemma 1: For a dynamic system ,and , , there exists a positive definite matrix satisfy , represents a dynamic system function, , and Indicates three gains, which are parameters with no special meaning. represents a positive definite matrix.

[0122] Case 1: If and , then the system is finite-time stable, and the stability time , is the initial state;

[0123] Case 2: If and , then the system is finite-time stable, and the stability time , Indicates the stabilization time of the system.

[0124] In this case, the Lyapunov function is constructed to prove the stability of the system. The Lyapunov function is:

[0125] ;

[0126] Where P is a positive definite symmetric matrix, , whose derivative with respect to time is:

[0127] ;

[0128] in, , .

[0129] Assume that:

[0130] ;

[0131] in, On this basis, by choosing appropriate matrices R and S, we can ensure .

[0132] Furthermore, assume that there exists a positive definite symmetric matrix P and a positive constant ε that satisfies the following matrix inequality:

[0133] ;

[0134] Then the system can be proved to be finite-time stable and the convergence time can be determined as For the boundary, The expression is:

[0135] .

[0136] At this point, the derivative of the Lyapunov function yields:

[0137] ;

[0138] According to formula (18), we can get:

[0139] ;

[0140] in, is an eigenvalue of P, and .

[0141] Rearranging the above formula yields:

[0142] .

[0143] Further combining equations (22) and (24), we can obtain:

[0144] .

[0145] From the above Lemma 1, we can see that if the first condition is satisfied, the system is stable in a finite time and the convergence time does not exceed the limit That is, the stability of the finite-time super-helical extended state observer is proved. Although the proof process shown in Lemma 1 does not involve the actual current control, the proof process can ensure that the control strategy of the permanent magnet synchronous motor can be designed based on the finite-time super-helical extended state observer.

[0146] S4: After proving the stability of the finite-time super-helical expansion state observer, the control rate of the permanent magnet synchronous motor current loop can be calculated based on the deadbeat predictive control model and the finite-time super-helical expansion state observer:

[0147] .

[0148] Further combined with vector resonant control to suppress the periodic disturbances in the permanent magnet synchronous motor system and reduce the current distortion caused by these periodic disturbances, the specific process of designing the vector resonant controller is as follows:

[0149] First, establish the transfer function of the vector resonant controller :

[0150] ;

[0151] in, and is the resonant gain, is the damping frequency, is the resonant frequency, and , , is the Laplace variable, and its physical meaning is The reciprocal of The rate of change.

[0152] It is also necessary to change the transfer function of the vector resonant controller to In the embodiment of the present invention, the discretization is performed by Tustin method. After discretization, the discretized transfer function is:

[0153] ;

[0154] in, , is the complex frequency domain of a discrete-time signal.

[0155] Adding the discretized transfer function to the current loop control and combining it with the finite-time super-helical expansion state observer, the final current loop controller can be obtained as:

[0156] .

[0157] The permanent magnet synchronous motor system can be controlled by the above current loop controller, which effectively improves the system control accuracy and stability.

[0158] In order to verify the effectiveness and advantages of the deadbeat predictive control method based on the finite time super-helical expansion state observer provided by the embodiment of the present invention, the present invention also conducts actual simulation verification, and analyzes and evaluates the current control method of the present invention in combination with the simulation results. Specifically, the simulation model of the permanent magnet synchronous motor servo control system established is shown in detail. Figure 2 ,exist Figure 2 In the simulation model shown, the speed loop adopts PI control, and the control strategy of the current loop is the deadbeat predictive control method based on the finite time super-helical expansion state observer proposed in the present invention. The specific verification process is as follows:

[0159] Given a mechanical angular velocity reference input of the permanent magnet synchronous motor , and use the motor encoder to obtain the electrical angle of the permanent magnet synchronous motor and angular velocity , where the electrical angle Used for coordinate transformation, converting the three-phase current into dq axis current. The current of the permanent magnet synchronous motor phase a, phase b and phase c can be obtained through the current sensor. , and , the above current can be transformed into the actual current of the motor d-axis (q-axis) through coordinate transformation , through the actual current The current loop control input can be obtained ;

[0160] Angular velocity The q-axis reference current required for speed closed-loop control calculation , the q-axis reference current is calculated Implement current loop control to achieve the required torque output, and then obtain the switching signal state vector of the inverter through coordinate transformation and SVPWM pulse modulation method ; Finally, the inverter is based on the DC bus voltage And the switching signal outputs three-phase current to drive the permanent magnet synchronous motor to operate.

[0161] based on Figure 2 The simulation model of the permanent magnet synchronous motor servo control system is rpm and 5 seconds with a sudden increase of 2 Under the condition of step disturbance, control simulation is performed using the traditional deadbeat predictive current control method and the deadbeat predictive control method based on the finite time super-helical expansion state observer provided in the embodiment of the present invention, and the following results are finally obtained:

[0162] Please see Figure 3 (b) and Figure 4 (b) for details. It can be seen from the figures that the d-axis and q-axis current fluctuations of the zero-beat predictive control method based on the finite-time super-helical expanded state observer are 0.14A and 0.13A respectively; please see Figure 3 (a) and Figure 4 (a) for details. It can be seen from the figures that the d-axis and q-axis current fluctuations of the traditional zero-beat predictive control method are 0.22A and 0.21A respectively. The d-axis and q-axis current fluctuations of the method of the present invention are much smaller than the d-axis and q-axis current fluctuations of the traditional zero-beat predictive control method, which verifies that the zero-beat predictive control method based on the finite-time super-helical expanded state observer can achieve high-precision current control of the permanent magnet synchronous motor.

[0163] Please see Figure 5 (a) and Figure 5 (b) for details, which respectively show the q-axis current Fourier analysis results of the traditional deadbeat predictive control and the deadbeat predictive control method based on the finite-time super-helical expanded state observer of the present invention. By comparing the results in the figures, it can be obtained that when the deadbeat predictive control method based on the finite-time super-helical expanded state observer is adopted, the total harmonic disturbance (THD) of the q-axis current is reduced by 0.86%, which verifies that the deadbeat predictive control method based on the finite-time super-helical expanded state observer can effectively estimate and compensate for periodic disturbances.

[0164] Please see Figure 6 (a) and Figure 6 (b) for details. It can be further concluded from the a-phase current curve that the deadbeat predictive control method based on the finite-time super-helical expanded state observer is adopted, which reduces the total harmonic disturbance (THD) of the a-phase current by 1.01%, thereby improving the stability of the permanent magnet synchronous motor system.

[0165] Please refer to Figures 7(a), 7(b), 7(c) and 7(d) for details. and 6 seconds ), it can be seen from the figure that compared with the traditional deadbeat predictive control method, the deadbeat predictive control method based on the finite time superhelical expansion state observer is significantly less sensitive to the inductance parameters; and from the current loop controller expression (29), it can be seen that the motor parameters resistance (R) and permanent magnet flux ( ) will not affect the control performance of the proposed algorithm.

[0166] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0167] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A deadbeat predictive control method, characterized in that: include: Establishing a dq-axis current equation of the permanent magnet synchronous motor in a synchronous rotating coordinate system, discretizing it to obtain a discrete current equation, and obtaining a predicted voltage equation based on the discrete current equation; According to the predicted voltage equation and the current loop disturbance of the permanent magnet synchronous motor, a deadbeat predictive control model based on the hyperlocal model is established. An extended state observation model of the dq axis current equation of the permanent magnet synchronous motor is established, and a finite time super helical extended state observer is designed based on finite time theory and super helical control theory; the finite time super helical extended state observer is designed as follows: ； in, , represents the estimated value of the state vector, Indicates the time, represents the sampling period, represents the control gain, express The stator voltage at time and is the error correction term, , is the current at time k, and is the observer gain value, , , , is the observer parameter; The control rate of the permanent magnet synchronous motor current loop is designed according to the deadbeat predictive control model and the finite time super-helical expansion state observer; and a vector resonance controller is designed in the current loop control to obtain a final current loop controller.

2. The deadbeat predictive control method according to claim 1, characterized in that: The dq-axis current equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system is: ； in, represents the stator current of the d-axis, represents the stator current of the q axis, represents the stator voltage of the d-axis, represents the stator voltage of the q-axis, represents the stator inductance of the d-axis, represents the stator inductance of the q-axis, is the stator resistance, is the electrical angular velocity, is the rotor flux.

3. The deadbeat predictive control method according to claim 2, wherein: The discrete current equation obtained by performing first-order forward differentiation on the dq axis current equation is: ； Among them, k represents any time; Then the predicted voltage equation at time k is: ； in, represents the sampling period, express The reference current value of the d-axis at the moment, express The reference current value of the q axis at the moment, express The stator voltage of the d-axis at time, express The stator current of the d-axis at time, for The electrical angular velocity at the moment, express The stator voltage of the q axis at time, express The stator current of the q-axis at time; To compensate for the delay of electronic components, the formula (3) is rewritten as: ； make , , , then the final predicted voltage equation obtained by equation (4) is: 。 4. The deadbeat predictive control method according to claim 3, characterized in that: The current loop disturbance includes non-periodic disturbance and periodic disturbance. The expressions of the non-periodic disturbance of the d-axis and q-axis of the permanent magnet synchronous motor are respectively: ； ； in, represents the non-periodic perturbation of the d-axis, represents the non-periodic disturbance of the q-axis, represents the cross-coupled perturbation of the d-axis, represents the cross-coupled disturbance of the q-axis, represents the known perturbation of the d-axis, represents a known disturbance on the q-axis, represents the disturbance of the d-axis caused by parameter perturbation, represents the disturbance of the q-axis caused by parameter perturbation, represents the external uncertain disturbance of the d-axis, represents the external uncertain disturbance of the q-axis, , is the nominal value of the d-axis stator inductance, is the nominal value of the q-axis stator inductance, is the nominal value of the stator inductance of the permanent magnet synchronous motor, is the nominal value of the stator resistance of the permanent magnet synchronous motor, is the nominal value of the permanent magnet synchronous motor rotor flux, , , .

5. The deadbeat predictive control method according to claim 4, characterized in that: The expressions of the periodic disturbances of the d-axis and q-axis of the permanent magnet synchronous motor are: ； in, represents the periodic perturbation of the d-axis, represents the periodic disturbance of the q-axis, represents the flux harmonic of the d-axis, represents the flux harmonic of the q-axis, represents the voltage harmonics of the d-axis, Indicates the voltage harmonics of the q-axis.

6. The deadbeat predictive control method according to claim 5, characterized in that: According to the predicted voltage equation of formula (5) and the current loop disturbance, the deadbeat predictive control model is obtained as follows: ； in, represents the current loop disturbance of the d-axis, represents the current loop disturbance of the q-axis, To control the gain, represents the d-axis voltage reference value at time k+1, Represents the q-axis voltage reference value at time k+1.

7. The deadbeat predictive control method according to claim 6, characterized in that: The process of establishing the extended state observation model of the dq axis current equation of the permanent magnet synchronous motor is as follows: Pick , , , , the expanded state observation model of the dq axis current equation is obtained as: ； in, , , , , .

8. The deadbeat predictive control method according to claim 7, characterized in that: The control rate of the current loop is designed as: 。 9. The deadbeat predictive control method according to claim 8, characterized in that: Transfer Function of Vector Resonant Controller for: ； in, and is the resonant gain, is the damping frequency, is the resonant frequency, and , ; The transfer function of the vector resonant controller is After discretization, the discretized transfer function is: ； in, ; And add the discretized transfer function to the current loop controller, and the final current loop controller is: ； in, is the reference current at time k.

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