A disc permanent magnet motor control method and system with adaptive dead zone compensation

Abstract

The present invention discloses a control method and system of a disc permanent magnet motor with adaptive dead zone compensation, including constructing a state equation, a state estimation equation and a state space equation of a permanent magnet synchronous motor through the structure of a Lumberg observer, constructing an energy observable matrix using an output matrix and a system matrix, and verifying the output of the energy observable system; establishing a characteristic equation so that the designed observer can finally converge, reducing the error between the estimated value of the disturbance observer and the actual value of the system, and realizing the digital control of the actual servo platform through the discrete energy observable matrix; analyzing the inverter A-phase bridge arm, Fourier decomposition of the three-phase current, and analyzing the stator harmonic components to obtain the three-phase harmonic current of the motor; designing an adaptive filter based on the NLMS algorithm, and improving the online dead zone compensation strategy for the dead zone effect. By introducing the Lumberg disturbance observer, this method can realize real-time measurement and adjustment of the nonlinear system, thereby effectively improving the performance indicators of the system.

Description

Technical Field

[0001] The present invention relates to the field of control theory and control engineering technology, and in particular to a disc-type permanent magnet motor control method and system with adaptive dead zone compensation. Background Art

[0002] The Luneburg disturbance observer is a nonlinear observer with strong disturbance suppression capability. Its design method originated in the 1950s and was first proposed by the German mathematician Lueneburg. The Luneburg disturbance observer is widely used in the modeling and control of various nonlinear systems, such as aircraft, wind power generation systems, permanent magnet synchronous motors and asynchronous motors.

[0003] The Lumberg disturbance observer introduces an observer to measure and adjust the system in real time, thereby effectively suppressing disturbances and improving system performance. Compared with traditional linear observers, the Lumberg disturbance observer has stronger robustness and adaptability, and can deal with uncertainty problems in nonlinear systems. At the same time, the Lumberg disturbance observer has the advantages of simple structure and small amount of calculation, which is convenient for practical application and promotion.

[0004] Pulse width modulation technology has been widely used in the field of motor control. However, due to the non-ideal switching characteristics of power devices, in order to avoid the "bridge arm direct pass" phenomenon of the inverter, a dead time is usually set during the switching of the upper and lower tubes of the same phase. However, the introduction of the dead time will cause problems such as output voltage distortion and torque pulsation. Although SiC-MOSFET has a higher switching frequency than traditional Si-MOSFET, the proportion of dead time in the entire switching cycle also increases. Therefore, this paper analyzes the mechanism of dead time effect and current harmonics, and designs a disc permanent magnet motor control strategy with adaptive dead time compensation to achieve the extraction and filtering of specified harmonics to better reduce the impact of the dead time effect. Summary of the invention

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a disc permanent magnet motor control method with adaptive dead zone compensation, which can effectively improve the performance of the control system, enhance the robustness and stability of the system, simplify the controller design, and is applicable to different types of control systems.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a control method for a disc permanent magnet motor with adaptive dead zone compensation, comprising: constructing an energy-observable matrix by using an output matrix and a system matrix through a structural construction equation of a Romberg observer, and verifying the output of the energy-observable system; establishing a characteristic equation to reduce the error between the estimated value of the disturbance observer and the actual value of the system, and realizing the digital control of the actual servo platform through a discrete energy-observable matrix; obtaining the three-phase harmonic current of the motor by analyzing the A-phase bridge arm of the inverter and the three-phase current of the Fourier decomposition, and analyzing the harmonic components of the stator; designing an adaptive filter based on the NLMS algorithm, and improving the online dead zone compensation strategy for the dead zone effect.

[0008] As a preferred solution of the control method of a disk permanent magnet motor with adaptive dead zone compensation described in the present invention, the state equation construction includes constructing a state estimation equation and a state space equation of the permanent magnet synchronous motor, and the state estimation equation is constructed by the structural frame of the Romberg observer, which are respectively expressed as:

[0009]

[0010] Among them, u is the input variable of the system, x is the state variable of the system, and y is the output variable of the system;

[0011] The state space equation of the permanent magnet synchronous motor includes: Since the load torque changes slower than the rotor mechanical speed in a sampling period during the operation of the motor system, the load torque is set in the design process of the observer. The state space equation of the permanent magnet synchronous motor is obtained:

[0012]

[0013] Among them, ω m is the mechanical angular velocity, T L is the load torque, B m is the damping coefficient, J is the moment of inertia, T e represents electromagnetic torque;

[0014] The output matrix and system matrix include checking the observability of the second-order system before designing the Lumberg state observer, verifying whether the output of the system can accurately reflect the state variables, and using the output matrix C and the system matrix A to construct the observability matrix N:

[0015]

[0016] As a preferred solution of the control method of a disk permanent magnet motor with adaptive dead zone compensation described in the present invention, the establishment of the characteristic equation includes: the system pole of the observer is in the left half plane, the characteristic equation is established and solved:

[0017]

[0018] Where, (A-LC) is the system state matrix of the Lumberg observer;

[0019] Assume that the desired node of the left half plane of the stable system is α=β<0, and substitute:

[0020]

[0021] When the motor coefficient Bm is ignored, as long as l1>0, l2<0 is satisfied, the error between the estimated value of the disturbance observer and the actual value of the system will eventually approach 0;

[0022] The discrete energy matrix includes the actual servo platform to realize digital control and discretization:

[0023]

[0024] Among them, T s is the system sampling period.

[0025] As a preferred solution of a disc permanent magnet motor control method with adaptive dead zone compensation described in the present invention, wherein: the analysis of the inverter A phase bridge arm includes obtaining the output voltage and current under the influence of the dead zone effect by analyzing the inverter A phase bridge arm, wherein V1 and V4 represent the upper and lower SiC-MOSFETs of the phase bridge arm, and D1 and D4 represent the corresponding freewheeling diodes. When the inverter works in an ideal state, V1 is turned on and V2 is turned off. At this time, the current flows out from the positive electrode of the DC power supply and then flows out from the A phase through V1. At this time, i a >0, V1 is turned off and V2 is turned on. At this time, the current flows out from phase A and flows into the negative electrode of the DC power supply after passing through V4. At this time, i a <0;

[0026] When the inverter works in the dead time, V1 and V4 are both in the off state. Since the motor winding is an inductive load, the three-phase current is continued through D1 and D4. a >0, the current continues to flow through the lower tube D4, and the voltage of phase A is when i a <0, the current continues to flow through the upper tube D1, and the voltage of phase A is

[0027] The Fourier decomposition of the three-phase current includes the following: the motor control system is accompanied by harmonics during operation, and the three-phase current is decomposed by Fourier to obtain:

[0028]

[0029] Among them, I an ,Ibn ,I cn They represent the amplitude of the nth stator harmonic current of three phases a, b, and c respectively. Indicates the initial phase angle of the nth harmonic.

[0030] As a preferred solution of the control method of a disc permanent magnet motor with adaptive dead zone compensation described in the present invention, the analysis of the stator harmonic components includes: through the analysis of the stator harmonic components, the 5th and 7th harmonics have the highest proportion and have the highest overall impact on the motor control system, so other higher-order harmonic components are ignored to obtain the motor three-phase harmonic current 0:

[0031]

[0032] After CLARKE and PARK coordinate transformation, we can get:

[0033]

[0034] Among them, i dl 、i ql Respectively represent the DC components of the d-axis and q-axis currents, i d5 ,i q5 ,i d7 ,i q7 Respectively represent the amplitudes of the 5th and 7th harmonic components of the d and q axis currents.

[0035] As a preferred solution of the control method of a disc permanent magnet motor with adaptive dead zone compensation described in the present invention, the NLMS algorithm includes: after the input signal x(n), the output signal y(n) is generated by a parameter-adjustable digital filter, and then the output signal y(n) is subtracted from the expected signal to obtain the signal error ε(n), and then the weight coefficient is continuously updated by the adaptive filtering algorithm to reduce the error, and finally the optimal filtering result is obtained, wherein the adaptive filtering algorithm adopts the LMS algorithm;

[0036] Error definition:

[0037] e(n)=d(n)-y(n)

[0038] Mean Square Error:

[0039] ε(n)=E[e 2 (n)] = E[d(n)-y(n)] 2

[0040] When the mean square error is minimum, the optimal weight coefficient is obtained:

[0041]

[0042] satisfy:

[0043]

[0044] The stochastic gradient method is used for method estimation:

[0045] W(n+1)=W(n)+μ·e(n)·x(n)

[0046] Among them, μ is the convergence coefficient;

[0047] When the input vector x(n) is too large, the weight of x(n) in μe(n)x(n) increases. By minimizing the interference principle, that is, in each iteration, the weight coefficient of the adaptive filter changes in a minimal way and is constrained by the updated filter output to prevent the weight of x(n) carrying harmonic signals from being too large:

[0048]

[0049] Where ψ is a positive constant.

[0050] As a preferred solution of the control method of a disc permanent magnet motor with adaptive dead zone compensation described in the present invention, the improved online dead zone compensation strategy includes calculating the current vector angle using the d and q axis currents filtered by the NLMS adaptive filter. At the same time, the rotor position angle θ is known by software decoding, and the current angle of phase A is when Then I A >0, otherwise I A <0, since the phase difference between the three-phase currents is 120°, the polarity of the other two-phase currents can be obtained in the same way. The constant amplitude is used for coordinate transformation, and the voltage amplitude to be compensated is:

[0051]

[0052] Where T represents a PWM switching cycle, U dc Indicates bus voltage;

[0053] The q-axis compensator is used to adjust θ e 、i d 、i q As input parameters, the CORDIC algorithm sine and cosine generator is used to extract the specified frequency harmonics. The harmonic amplitude weight is adjusted online based on the gradient descent method to obtain the specified 6th and 12th harmonics in the d and q axis currents, reduce the content of d and q axis high-order harmonics in the forward channel, and set the harmonic amount to zero as the target value. The PI controller is used to obtain the d and q axis voltages u to be compensated. dcom 、u qcom .

[0054] Another object of the present invention is to provide a system of a disc permanent magnet motor control method with adaptive dead zone compensation, which can effectively reduce the dead zone effect of the control system and improve the tracking accuracy and response speed of the system.

[0055] A system for a disc-type permanent magnet motor control method with adaptive dead zone compensation, characterized in that it includes a data acquisition module, a model building module, a dead zone compensation module, and a communication interface module;

[0056] The data acquisition module is responsible for real-time acquisition of the input and output data of the system, including input signals, output signals and control signals, converting the above signals into digital signals, and sampling them at a certain sampling frequency to provide input data for subsequent modules;

[0057] The model building module uses the NLMS algorithm to build a nonlinear model based on the collected input and output data to describe the dynamic characteristics of the system and provide a basis for subsequent prediction and control;

[0058] The dead zone compensation module realizes online dead zone compensation, and adjusts the control signal of the system in real time according to the output of the controller module, eliminates the dead zone in the control signal, and enables the system to achieve precise control;

[0059] The communication interface module realizes data transmission and communication between various modules, supports real-time and high-speed data transmission, and ensures the real-time and accuracy of the system.

[0060] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the processor implements the steps of a disc permanent magnet motor control method with adaptive dead zone compensation.

[0061] A computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, the computer program implements the steps of a method for controlling a disc-type permanent magnet motor with adaptive dead zone compensation.

[0062] Beneficial effects of the present invention: The present method can effectively reduce the dead zone effect of the control system, improve the tracking accuracy and response speed of the system, and thus improve the overall performance of the control system. The NLMS algorithm can adapt to changes in system parameters and external environment, and adjust the control quantity in real time, thereby enhancing the robustness of the control system and improving the stability of the system when facing uncertain factors. Through online dead zone compensation, the overshoot of the system can be reduced, the system oscillation can be reduced, and thus the stability of the control system can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0064] Figure 1 A schematic flow chart of a method for controlling a disc-type permanent magnet motor with adaptive dead zone compensation is provided in accordance with an embodiment of the present invention.

[0065] Figure 2 A Romberg observer control block diagram of a disc permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0066] Figure 3 A block diagram of a Romberg disturbance observer structure of a disk permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0067] Figure 4 An A-phase bridge arm current polarity diagram of a disc permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0068] Figure 5 A principle block diagram of an adaptive filter of a disc permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0069] Figure 6 A Simulink simulation diagram of a Romberg disturbance observer for a disc permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0070] Figure 7 A disturbance observation diagram of a Romberg disturbance observer for a disk permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0071] Figure 8 A sinusoidal disturbance observation diagram of a Romberg disturbance observer for a disk permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention.

[0072] Fig. 9 Waveforms after filtering of d-axis and q-axis currents of a disk permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention

[0073] Fig.10 A schematic diagram of the working process of a system of a disc permanent magnet motor control method with adaptive dead zone compensation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0074] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0075] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0076] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0077] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0078] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0079] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] Example 1

[0081] Reference Figure 1 - Figure 5 , which is the first embodiment of the present invention, provides a disc-type permanent magnet motor control method with adaptive dead zone compensation, comprising:

[0082] S1: The equations are constructed through the structure of the Lumberg observer, and the observable matrix is ​​constructed using the output matrix and the system matrix to verify the output of the observable system.

[0083] Furthermore, the constructing state equation, state estimation equation and state space equation of the permanent magnet synchronous motor includes constructing the state estimation equation by the structural frame of the Romberg observer, which are respectively expressed as:

[0084]

[0085]

[0086] Among them, u is the input variable of the system, x is the state variable of the system, and y is the output variable of the system;

[0087] The state space equation of the permanent magnet synchronous motor includes: Since the load torque changes relatively slowly than the rotor mechanical speed during the operation of the motor system, the load torque is set in the design process of the observer. The state space equation of the permanent magnet synchronous motor is obtained:

[0088]

[0089] Among them, ω m is the mechanical angular velocity, T L is the load torque, B m is the damping coefficient, J is the moment of inertia, T e represents electromagnetic torque;

[0090] The output matrix and system matrix include checking the observability of the second-order system before designing the Lumberg state observer, verifying whether the output of the system can accurately reflect the state variables, and constructing the observability matrix N using the output matrix C and the system matrix A:

[0091]

[0092] It should be noted that the observable matrix includes the above-mentioned matrix N, whose rank is 2 and is a full-rank matrix. The motor system is an observable system. The following equations are obtained:

[0093]

[0094] in,

[0095] S2: Establish the characteristic equation to reduce the error between the estimated value of the disturbance observer and the actual value of the system, and realize the digital control of the actual servo platform through the discrete energy matrix.

[0096] Furthermore, the establishment of the characteristic equation includes, the system poles of the observer are in the left half plane, establishing the characteristic equation and solving it:

[0097]

[0098] Where, (A-LC) is the system state matrix of the Lumberg observer;

[0099] Assume that the desired node of the left half plane of the stable system is α=β<0, and substitute:

[0100]

[0101] When the motor coefficient Bm is ignored, as long as l1>0, l2<0 is satisfied, the error between the estimated value of the disturbance observer and the actual value of the system will eventually approach 0;

[0102] The discrete energy matrix includes the actual servo platform, which must be discretized in order to realize digital control:

[0103]

[0104] Among them, T s is the system sampling period.

[0105] S3: By analyzing the inverter A-phase bridge arm, Fourier decomposition of the three-phase current, and analysis of the stator harmonic components, the three-phase harmonic current of the motor is obtained.

[0106] Furthermore, the analysis of the inverter A phase bridge arm includes, by analyzing the inverter A phase bridge arm, obtaining the output voltage and current under the influence of the dead zone effect, including V1, V4 represents the upper and lower SiC-MOSFETs of the phase bridge arm, D1, D4 represents the corresponding freewheeling diodes, when the inverter works in an ideal state, if V1 is turned on and V2 is turned off, at this time, the current flows out from the positive electrode of the DC power supply and then flows out from the A phase through V1, at this time i a >0, if V1 is turned off and V2 is turned on, the current flows out from phase A and flows into the negative electrode of the DC power supply after passing through V4. At this time, i a <0;

[0107] When the inverter works in the dead time, V1 and V4 are both in the off state. Since the motor winding is an inductive load, the three-phase current is continued through D1 and D4. When ia>0, the current continues through the lower tube D4. At this time, the voltage of phase A is when i a<0, the current continues to flow through the upper tube D1, and the voltage of phase A is

[0108] The Fourier decomposition of the three-phase current includes that a large number of harmonics are accompanied during the operation of the motor control system, and the three-phase current is decomposed by Fourier to obtain:

[0109]

[0110] Among them, I an ,I bn ,I cn They represent the amplitude of the nth stator harmonic current of three phases a, b, and c respectively. Indicates the initial phase angle of the nth harmonic.

[0111] Furthermore, the analysis of the stator harmonic components includes analyzing the stator harmonic components, among which the 5th and 7th harmonics account for the largest proportion and have the greatest overall impact on the motor control system. Therefore, other higher-order harmonic components are usually ignored, and the motor three-phase harmonic current 0 is obtained:

[0112]

[0113] After CLARKE and PARK coordinate transformation, we can get:

[0114]

[0115] Among them, i dl 、i ql Respectively represent the DC components of the d-axis and q-axis currents, i d5 ,i q5 ,i d7 ,i q7 Respectively represent the amplitudes of the 5th and 7th harmonic components of the d and q axis currents.

[0116] S4: Design an adaptive filter based on the NLMS algorithm and improve the online dead zone compensation strategy to address the dead zone effect.

[0117] Furthermore, the NLMS algorithm includes: the design of the adaptive filter based on the NLMS algorithm includes: after the input signal x(n), the output signal y(n) is generated by the parameter-adjustable digital filter, and the output signal y(n) is subtracted from the expected signal to obtain the signal error ε(n), and then the weight coefficient is continuously updated by the adaptive filtering algorithm to make the error smaller and smaller, and finally obtain the optimal filtering result, wherein the adaptive filtering algorithm adopts the LMS algorithm;

[0118] Error definition:

[0119] e(n)=d(n)-y(n)

[0120] Mean Square Error:

[0121] ε(n)=E[e 2 (n)] = E[d(n)-y(n)] 2

[0122] When the mean square error is minimum, the optimal weight coefficient is obtained:

[0123]

[0124] satisfy:

[0125]

[0126] The stochastic gradient method is used for method estimation:

[0127] W(n+1)=W(n)+μ·e(n)·x(n)

[0128] Among them, μ is the convergence coefficient. The larger its value, the faster the convergence speed, but the stability is reduced. Therefore, it is necessary to adjust the parameters through continuous experiments.

[0129] When the input vector x(n) is too large, the weight of x(n) in μe(n)x(n) will increase. x(n) is accompanied by unknown harmonic signals. In order to avoid the amplification of gradient noise, the NLMS algorithm is used. By minimizing the interference principle, that is, in each iteration process, the weight coefficient of the adaptive filter is changed in a minimum manner and is subject to the updated filter output constraint, thereby preventing the weight of x(n) carrying harmonic signals from being too large:

[0130]

[0131] Where ψ is a positive constant.

[0132] Furthermore, based on the above-mentioned d-axis and q-axis current harmonic analysis principles and the NLMS filtering process, the adaptive filter designed in this paper uses the DC value as the reference signal, and is specifically implemented as follows:

[0133]

[0134] Among them, X is a constant, the initial value of W is the initial weight of the input signal X, and an iteration is performed after each d-axis and q-axis current sampling.

[0135] Furthermore, the improved online dead zone compensation strategy includes calculating the current vector angle using the d and q axis currents filtered by the NLMS adaptive filter. At the same time, the rotor position angle θ is known by software decoding, and the current angle of phase A is like Then IA >0, otherwise I A <0. Since the phase difference between the three-phase currents is 120°, the polarity of the other two-phase currents can be obtained by the same logic. The constant amplitude is used for coordinate transformation, so the voltage amplitude to be compensated is:

[0136]

[0137] Where T represents a PWM switching cycle, U dc Indicates bus voltage;

[0138] The q-axis compensator is used to adjust θ e 、i d 、i q As input parameters, the CORDIC algorithm sine and cosine generator is used to extract the specified frequency harmonics. The online adjustment of the harmonic amplitude weight is realized based on the gradient descent method to obtain the specified 6th and 12th harmonics in the d and q axis currents. In order to reduce the content of d and q axis high-order harmonics in the forward channel, the harmonic amount is set to zero as the target value, and the d and q axis voltages u to be compensated are obtained through the PI controller. dcom 、u qcom .

[0139] Example 2

[0140] Reference Figure 6 - Fig. 9 , which is an embodiment of the present invention, provides a disc permanent magnet motor control method with adaptive dead zone compensation. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0141] The Lumberg disturbance observer model was built on the MATLAB / Simulink platform. Figure 6 As shown, the coefficient calculations at each level are completed in the script file. Set the motor torque to 10N·m, the maximum speed to 1000rpm, and the system sampling period to T s =5e-6. The motor starts with a load of 5N·m. After the motor runs stably, the load is suddenly increased to 10N·m at 0.15s. After the motor stabilizes again, the load is suddenly reduced at 0.3s.

[0142] from Figure 7 From the disturbance observation results, it can be found that when the motor is started with load, the Lumberg disturbance observer can track the load torque within 0.02s; at the same time, at the moment of sudden load increase of 0.15s and sudden load decrease of 0.3s, the disturbance observer can quickly follow the given value, and there is no obvious fluctuation during the observation process.

[0143] In order to verify the dynamic following performance of the Lumberg disturbance observer designed in this paper for continuous disturbances, a continuous triangular wave disturbance is introduced. Figure 8 It can be seen that the Lumberg observer can quickly reach the given disturbance in about 0.02s, the tracking trend is relatively stable and the observation error is between -0.15 and 0.15N·m. From the analysis of the above simulation waveforms, it can be seen that the Lumberg observer designed in this paper has good observation effects in both the steady-state and dynamic performance of motor load disturbances.

[0144] According to the above analysis, this section builds a simulation model based on the MATLAB / Simulink simulation platform. The motor set torque is 10N·m, the load torque is 5N·m, and the maximum speed is 1000rpm. The simulation is performed at dead time of 5μs, 3μs, and 1μs, and the stator three-phase current waveforms before and after optimization are compared and analyzed.

[0145] Before dead zone compensation, the A-phase stator current waveform of the motor control system was obviously distorted. After harmonic analysis, the THD reached 6.14%, 3.02%, and 2.45% respectively, the 5th harmonic accounted for approximately 3.7%, 1.45%, and 0.4% respectively, and the 7th harmonic accounted for approximately 3.2%, 0.8%, and 0.38% respectively; the distortion of the stator current was significantly improved, and the total harmonic distortion rate was reduced to 2.86%, 2.88%, and 2.4% respectively, the 5th harmonic accounted for 0.65%, 0.75%, and 0.23%, and the 7th harmonic accounted for 0.32%, 0.27%, and 0.21%.

[0146] In summary, through simulation analysis, it can be seen that the online dead zone compensation strategy based on the NLMS algorithm has a good inhibitory effect on the negative impact of the dead zone effect, effectively reducing the distortion of the three-phase stator current of the motor due to the dead zone time, and correspondingly improving the speed and torque steady-state performance of the permanent magnet synchronous motor control system. The larger the dead zone time, the more obvious the improvement effect.

[0147] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0148] Example 3

[0149] The third embodiment of the present invention is different from the first two embodiments in that:

[0150] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0151] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0152] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0153] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0154] Example 4

[0155] Reference Fig.10 , which is an embodiment of the present invention, provides a disc permanent magnet motor control system with adaptive dead zone compensation, characterized in that it includes a data acquisition module, a model building module, a dead zone compensation module, and a communication interface module.

[0156] The data acquisition module is responsible for real-time acquisition of the input and output data of the system, including input signals, output signals and control signals, converting the above signals into digital signals and sampling them at a certain sampling frequency to provide input data for subsequent modules.

[0157] The model building module uses the NLMS algorithm to build a nonlinear model based on the collected input and output data to describe the dynamic characteristics of the system and provide a basis for subsequent prediction and control.

[0158] The dead zone compensation module realizes online dead zone compensation. According to the output of the controller module, the control signal of the system is adjusted in real time to eliminate the dead zone in the control signal and realize precise control of the system.

[0159] The communication interface module realizes data transmission and communication between various modules, supports real-time and high-speed data transmission, and ensures the real-time and accuracy of the system.

[0160] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A control method for a disc-type permanent magnet motor with adaptive dead zone compensation, characterized in that: include, Through the structure of the Lumberg observer, the equation is constructed, and the observable matrix is ​​constructed using the output matrix and the system matrix to verify the output of the observable system. The constructing state equation includes constructing a state estimation equation and a state space equation of the permanent magnet synchronous motor. The state estimation equation is constructed by the structural frame of the Romberg observer, which are respectively expressed as: Among them, u is the input variable of the system, x is the state variable of the system, and y is the output variable of the system; The state space equation of the permanent magnet synchronous motor includes: Since the load torque changes slower than the rotor mechanical speed in a sampling period during the operation of the motor system, the load torque is set in the design process of the observer. The state space equation of the permanent magnet synchronous motor is obtained: Among them, ω m is the mechanical angular velocity, T L is the load torque, B m is the damping coefficient, J is the moment of inertia, T e represents electromagnetic torque; The output matrix and system matrix include checking the observability of the second-order system before designing the Lumberg state observer, verifying whether the output of the system can accurately reflect the state variables, and using the output matrix C and the system matrix A to construct the observability matrix N: Establish the characteristic equation to reduce the error between the estimated value of the disturbance observer and the actual value of the system, and realize the digital control of the actual servo platform through the discrete energy matrix; By analyzing the inverter A-phase bridge arm, Fourier decomposition of the three-phase current, and the stator harmonic components, the motor three-phase harmonic current is obtained; Design an adaptive filter based on the NLMS algorithm and improve the online dead zone compensation strategy for the dead zone effect; The improved online dead zone compensation strategy includes calculating the current vector angle using the d-axis and q-axis currents filtered by the NLMS adaptive filter. At the same time, the rotor position angle θ is known by software decoding, and the current angle of phase A is when Then I A >0, otherwise I A <0, since the phase difference between the three-phase currents is 120°, the polarity of the other two-phase currents can be obtained in the same way. The constant amplitude is used for coordinate transformation, and the voltage amplitude to be compensated is: Where T represents a PWM switching cycle, U dc Indicates bus voltage; The q-axis compensator is used to adjust θ e 、i d 、i q As input parameters, the CORDIC algorithm sine and cosine generator is used to extract the specified frequency harmonics. The harmonic amplitude weight is adjusted online based on the gradient descent method to obtain the specified 6th and 12th harmonics in the d and q axis currents, reduce the content of d and q axis high-order harmonics in the forward channel, and set the harmonic amount to zero as the target value. The PI controller is used to obtain the d and q axis voltages u to be compensated. dcom 、u qcom .

2. A disc permanent magnet motor control method with adaptive dead zone compensation as claimed in claim 1, characterized in that: The establishment of the characteristic equation includes that the system poles of the observer are in the left half plane, the characteristic equation is established and solved: Where, (A-LC) is the system state matrix of the Lumberg observer; Assume that the desired node of the left half plane of the stable system is α=β<0, and substitute: When the motor coefficient Bm is ignored, as long as l1>0, l2<0 is satisfied, the error between the estimated value of the disturbance observer and the actual value of the system will eventually approach 0; The discrete energy matrix includes the actual servo platform to realize digital control and discretization: Among them, T s is the system sampling period.

3. A disc permanent magnet motor control method with adaptive dead zone compensation as claimed in claim 2, characterized in that: The analysis of the inverter A phase bridge arm includes obtaining the output voltage and current under the influence of the dead zone effect by analyzing the inverter A phase bridge arm, wherein V1 and V4 represent the upper and lower SiC-MOSFETs of the phase bridge arm, and D1 and D4 represent the corresponding freewheeling diodes. When the inverter works in an ideal state, V1 is turned on and V2 is turned off. At this time, the current flows out from the positive electrode of the DC power supply and then flows out from the A phase through V1. At this time, i a >0, V1 is turned off and V2 is turned on. At this time, the current flows out from phase A and flows into the negative electrode of the DC power supply after passing through V4. At this time, i a <0; When the inverter works in the dead time, V1 and V4 are both in the off state. Since the motor winding is an inductive load, the three-phase current is continued through D1 and D4. a >0, the current continues to flow through the lower tube D4, and the voltage of phase A is when i a <0, the current continues to flow through the upper tube D1, and the voltage of phase A is The Fourier decomposition of the three-phase current includes the following: the motor control system is accompanied by harmonics during operation, and the three-phase current is decomposed by Fourier to obtain: Among them, I an ,I bn ,I cn They represent the amplitude of the nth stator harmonic current of three phases a, b, and c respectively. Indicates the initial phase angle of the nth harmonic.

4. A disc-type permanent magnet motor control method with adaptive dead zone compensation as claimed in claim 3, characterized in that: The analysis of the stator harmonic components includes: through the analysis of the stator harmonic components, the 5th and 7th harmonics account for the largest proportion and have the greatest overall impact on the motor control system. Therefore, other higher-order harmonic components are ignored, and the motor three-phase harmonic current 0 is obtained: After CLARKE and PARK coordinate transformation, we can get: Among them, i dl 、i ql Respectively represent the DC components of the d-axis and q-axis currents, i d5 ,i q5 ,i d7 ,i q7 Respectively represent the amplitudes of the 5th and 7th harmonic components of the d and q axis currents.

5. A disc-type permanent magnet motor control method with adaptive dead zone compensation as claimed in claim 4, characterized in that: The NLMS algorithm includes: after the input signal x(n), the output signal y(n) is generated by a parameter-adjustable digital filter, and then the output signal y(n) is subtracted from the expected signal to obtain the signal error ε(n), and then the weight coefficient is continuously updated through the adaptive filtering algorithm to reduce the error and obtain the optimal filtering result, wherein the adaptive filtering algorithm adopts the LMS algorithm; Error definition: e(n)=d(n)-y(n) Mean Square Error: ε(n)=E[e 2 (n)]=E[d(n)-y(n)] 2 When the mean square error is minimum, the optimal weight coefficient is obtained: satisfy: The stochastic gradient method is used for method estimation: W(n+1)=W(n)+μ·e(n)·x(n) Among them, μ is the convergence coefficient; When the input vector x(n) is too large, the weight of x(n) in μe(n)x(n) increases. By minimizing the interference principle, that is, in each iteration, the weight coefficient of the adaptive filter changes in a minimal way and is constrained by the updated filter output to prevent the weight of x(n) carrying harmonic signals from being too large: Where ψ is a positive constant.

6. A system using a disc permanent magnet motor control method with adaptive dead zone compensation as claimed in any one of claims 1 to 5, characterized in that: It includes data acquisition module, model building module, dead zone compensation module and communication interface module; The data acquisition module is responsible for real-time acquisition of the input and output data of the system, including input signals, output signals and control signals, converting the above signals into digital signals, and sampling them at a certain sampling frequency to provide input data for subsequent modules; The model building module uses the NLMS algorithm to build a nonlinear model based on the collected input and output data to describe the dynamic characteristics of the system and provide a basis for subsequent prediction and control; The dead zone compensation module realizes online dead zone compensation, and adjusts the control signal of the system in real time according to the output of the controller module, eliminates the dead zone in the control signal, and enables the system to achieve precise control; The communication interface module realizes data transmission and communication between various modules, supports real-time and high-speed data transmission, and ensures the real-time and accuracy of the system.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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