A Method for Suppressing Current Harmonic Disturbance of a Permanent Magnet Synchronous Motor and a Motor System

Abstract

The present invention relates to the field of motor control technology, and specifically provides a method for suppressing current harmonic disturbances of a permanent magnet synchronous motor and a motor system. First, a mathematical model of a permanent magnet synchronous motor considering harmonic disturbances under a synchronous rotating coordinate system d-q axis is constructed to provide a theoretical basis for the design of a subsequent control strategy. Based on this, an improved resonant controller is set and embedded into an extended state observer to achieve comprehensive estimation of d-q axis non-periodic disturbances and periodic harmonic disturbances. Finally, an enhanced current loop anti-disturbance controller based on the improved resonant extended state observer is constructed to eliminate undesirable peaks and achieve comprehensive suppression of non-periodic disturbances and periodic disturbances. The present invention can suppress non-periodic and periodic disturbances while eliminating undesirable peaks, avoiding system instability caused by noise amplification, and significantly improving the steady-state performance and robustness of the permanent magnet synchronous motor current control.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and in particular relates to a method for suppressing current harmonic disturbances of a permanent magnet synchronous motor and a motor system. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) have been widely used in applications such as electric vehicles and precision equipment due to their high reliability, high efficiency, and high power density. However, the non-periodic and periodic harmonic disturbances encountered during motor operation severely impact system performance and control accuracy. Active Disturbance Rejection Control (ADRC), a control method that does not rely on precise models, shows broad application prospects in PMSM control due to its efficient estimation and compensation capabilities for system disturbances. The Extended State Observer (ESO), a core component of ADRC, estimates the system state and disturbances, effectively improving the system's interference rejection performance. However, due to limited bandwidth, traditional ESOs struggle to simultaneously accurately estimate disturbances and effectively suppress measurement noise, hindering further improvements in system performance. Furthermore, traditional resonance-based ADRC algorithms can introduce undesirable peaking, amplifying noise in this frequency band and impacting system stability. Summary of the Invention

[0003] In view of this, the present invention aims to provide a method for suppressing current harmonic disturbances in a permanent magnet synchronous motor, designs an improved resonant controller, and embeds the improved resonant controller into an extended state observer for disturbance estimation, thereby effectively suppressing non-periodic disturbances and periodic harmonic disturbances in motor operation, eliminating undesirable peaks, and improving motor system performance.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] The present invention provides a method for suppressing current harmonic disturbances in a permanent magnet synchronous motor, comprising:

[0006] A mathematical model of the permanent magnet synchronous motor current loop considering the total disturbance is constructed, and the total disturbance of the dq axis is defined as the expansion state of the motor system; the mathematical model of the permanent magnet synchronous motor current loop considering the total disturbance is:

[0007] ;

[0008] in, Indicates time, represents the d-axis stator current, represents the q-axis stator current, represents the current control gain, , Indicates the nominal value of the motor’s inductance, represents the d-axis stator reference voltage, represents the q-axis stator reference voltage, represents a known perturbation about the d-axis, represents a known disturbance on the q-axis, represents the total disturbance on the d-axis, represents the total disturbance on the q-axis;

[0009] Design an improved resonant controller for any frequency harmonics for:

[0010] ;

[0011] in, represents the resonant gain, represents the resonant bandwidth, represents the resonant frequency, , represents the Laplace complex frequency variable, represents the bandwidth of the extended state observer;

[0012] The improved resonant controller is embedded in the extended state observer to estimate the total disturbance.

[0013] The total disturbance estimation is introduced into the control end as a feedforward signal, and the control law is designed to compensate the total disturbance in the mathematical model of the permanent magnet synchronous motor current loop.

[0014] Preferably, the total disturbance includes: non-periodic disturbance and periodic harmonic disturbance.

[0015] Preferably, the calculation formula for the harmonic disturbance of the current loop dq axis is:

[0016] ;

[0017] in, , represents the harmonic disturbance of dq axis, represents the harmonic disturbance of the d-axis, represents the harmonic disturbance of the q-axis, , represents the dq axis voltage harmonics caused by the inverter dead zone effect, represents the d-axis voltage harmonics caused by the inverter dead zone effect, represents the q-axis voltage harmonics caused by the inverter dead-time effect, , represents the permanent magnet flux harmonics under the dq axis, represents the d-axis flux harmonic, represents the q-axis flux harmonic, , Indicates the number of pole pairs of the motor, is the mechanical angular velocity of the motor, , Indicates the d-axis inductance and the nominal value of the d-axis inductance The error, , Indicates the q-axis inductance and the nominal value of the q-axis inductance The surface-mounted permanent magnet synchronous motor meets the error of ;

[0018] The calculation formula for the non-periodic disturbance of the current loop dq axis is:

[0019] ;

[0020] in, represents the d-axis non-periodic perturbation, represents the q-axis non-periodic disturbance, , Indicates stator resistance With the nominal value of resistance The error, represents the d-axis uncertainty disturbance, represents the q-axis uncertainty disturbance.

[0021] Preferably, the total disturbance of the dq axes is defined as the expanded state of the motor system, and the expanded state system is obtained as:

[0022] ;

[0023] ;

[0024] in, is the derivative of the total disturbance about the d-axis, is the derivative of the total disturbance about the q axis.

[0025] Preferably, when suppressing multi-frequency harmonic disturbances, the improved resonant controller The expression is:

[0026] ;

[0027] in, Represents the resonance gain at different frequencies, Represents the resonant bandwidth of different frequencies, Indicates the resonant frequencies of different frequencies.

[0028] Preferably, the 6th harmonic disturbance and the 12th harmonic disturbance are suppressed. , .

[0029] Preferably, the improved resonant controller is embedded in the extended state observer to obtain the improved d-axis and q-axis resonant-extended state observer:

[0030] ;

[0031] ;

[0032] in, represents the d-axis stator current estimate, represents the q-axis stator current estimate, represents the total disturbance estimate of the d-axis, represents the total disturbance estimate of the q-axis, represents the d-axis non-periodic perturbation estimate, represents the q-axis non-periodic disturbance estimate, represents the d-axis harmonic disturbance estimate, represents the q-axis harmonic disturbance estimate, 、 、 and is the state variable of the improved resonant controller, and is the gain coefficient of the extended state observer, and Represents an intermediate variable.

[0033] Preferably, the control law is:

[0034] ;

[0035] in, represents the d-axis stator reference voltage, represents the q-axis stator reference voltage, represents the d-axis reference current, represents the q-axis reference current, is a constant used to compensate for known disturbances in the d-axis. is a constant used to compensate for the known disturbance on the q axis. , represents the d-axis current loop controller gain, , Represents the q-axis current loop controller gain.

[0036] Another aspect of the present invention provides a motor system that adopts a method for suppressing current harmonic disturbances of a permanent magnet synchronous motor.

[0037] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0038] This invention constructs an extended state observer (ESO) with an improved resonant controller to estimate and suppress non-periodic and harmonic disturbances along the dq axes. By optimizing the resonant characteristics and observer structure, it enhances harmonic suppression while effectively eliminating unwanted peaks near the resonant frequency. Compared with traditional active disturbance rejection control (ADRC) and traditional resonant ADRC, this invention significantly suppresses current harmonics, avoiding the risk of noise amplification near the resonant frequency and affecting system stability, thereby significantly improving the system's harmonic suppression capability and operational smoothness.

[0039] The present invention can effectively resist the adverse effects of parameter changes under complex working conditions, ensure that the system has strong anti-interference performance and reliability, and can maintain excellent control performance under system parameter changes. Compared with traditional control methods, the enhanced active anti-disturbance control method of the present invention has significant advantages in harmonic suppression, system stability and parameter robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 This is a structural block diagram of a permanent magnet synchronous motor control system to which the method for suppressing current harmonic disturbances of a permanent magnet synchronous motor provided by an embodiment of the present invention is applied;

[0042] Figure 2 A method for suppressing current harmonic disturbances in a permanent magnet synchronous motor is provided according to an embodiment of the present invention;

[0043] Figure 3 1 is a block diagram of an enhanced active disturbance rejection control structure based on an improved resonance-extended state observer according to an embodiment of the present invention;

[0044] Figure 4 According to the embodiment of the present invention, different Bode plot of the conventional resonant controller below;

[0045] Figure 5 According to the embodiment of the present invention, different Bode plot of the conventional resonant controller below;

[0046] Figure 6 According to the embodiment of the present invention, different Bode plot of the improved resonant controller below;

[0047] Figure 7According to the embodiment of the present invention, different Bode plot of the improved resonant controller below;

[0048] Figure 8 is a Bode diagram of the interference estimation error and actual interference transfer function under different observers provided by an embodiment of the present invention;

[0049] Figure 9 is a Bode plot of the closed-loop system output and actual disturbance transfer function under different active disturbance rejection algorithms provided by an embodiment of the present invention;

[0050] Figure 10 This is a diagram showing the dq axis and phase current waveforms of a conventional active disturbance rejection control system under a speed of 150 r / min and a load of 3 N·m according to an embodiment of the present invention;

[0051] Figure 11 This is a diagram showing the dq axis and phase current waveforms of a conventional resonant auto-disturbance rejection control system at a speed of 150 r / min and a load of 3 N·m according to an embodiment of the present invention;

[0052] Figure 12 dq axis and phase current waveforms of the enhanced active disturbance rejection control at a speed of 150 r / min and a load of 3 N·m provided by an embodiment of the present invention;

[0053] Figure 13 dq axis current waveforms of inductance mismatch at a speed of 150 r / min and a load of 6 N·m according to an embodiment of the present invention;

[0054] Figure 14 dq axis current waveforms of resistance mismatch at a speed of 150 r / min and a load of 6 N·m provided by an embodiment of the present invention;

[0055] Figure 15 1 is a dq axis current waveform diagram of flux mismatch at a speed of 150 r / min and a load of 6 N·m according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions 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 to the present invention. Similar elements in different embodiments use associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present invention to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present invention are not shown or described in the specification. This is to avoid the core part of the present invention being overwhelmed by too much description. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0057] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various orders in the description and the drawings are only for the purpose of clearly describing a certain embodiment and are not intended to be a required order, unless otherwise specified that a certain order must be followed.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0059] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0061] In one embodiment of the present invention, a method for suppressing current harmonic disturbances of a permanent magnet synchronous motor based on enhanced auto-disturbance rejection is provided. The method is specifically applied to Figure 1 In the permanent magnet synchronous motor system shown, periodic harmonic disturbances and non-periodic disturbances are estimated and compensated. This permanent magnet synchronous motor system employs a cascaded dual-closed-loop structure comprising a speed loop and a current loop. Specifically, the speed loop is regulated by a PI controller, outputting a reference current for the q-axis; the current loop is regulated by the invented control scheme, outputting reference voltages for the d-axis and q-axis. Furthermore, the designed harmonic suppression link with multiple frequency-selective characteristics is integrated into the extended state observer, forming an enhanced active disturbance rejection control framework together with the control law. The integral link within the observer is used to estimate non-periodic disturbances, while the introduced harmonic suppression link accurately estimates multiple harmonic disturbances.

[0062] Among them, the speed command , which is the speed value that the motor is expected to reach and serves as the input target of the entire control system.

[0063] The position / speed sensor is used to obtain the actual speed of the motor and perform closed-loop feedback control on the actual speed, so that the system can correct the speed deviation in real time and improve the control accuracy.

[0064] The PI speed regulator is used to receive the speed error obtained by comparing the actual speed with the speed command, and processes the error through proportional (P) and integral (I) operations, so that the system can accurately track the speed command in steady state.

[0065] d-axis current command , which is used to control the magnetic flux of the motor.

[0066] q-axis current command , which is used to adjust the motor torque.

[0067] The d-axis enhanced ADRC and q-axis enhanced ADRC are used to control the d-axis and q-axis currents respectively, suppressing the influence of various disturbances in the system, such as load changes, motor parameter changes, etc. on current control. According to the reference value and feedback value of the current, the corresponding d-axis and q-axis voltage commands are output. and , so that the actual current can accurately track the command current and ensure the stable operation of the motor.

[0068] The abc / dq conversion is used to convert the current feedback value in the three-phase stationary coordinate system (abc) into the current value in the two-phase rotating coordinate system (dq).

[0069] dq / Transformation is used to convert signals between different control links.

[0070] SVPWM (Space Vector Pulse Width Modulation) is used to receive Voltage command in coordinate system and , the signal that controls the inverter switch tube is calculated through a specific algorithm.

[0071] The inverter, which consists of multiple power switching tubes, converts DC power into three-phase AC power according to the switching signal output by the SVPWM module, which is used to drive the three-phase winding of the permanent magnet synchronous motor so that the motor can rotate normally.

[0072] Current sampling is used to sample the three-phase AC current in real time during the operation of the motor, obtain the actual operating current information of the motor, and feed the current information back to the control system for comparison with the current command to form a current closed-loop control.

[0073] For the current harmonic disturbance of the above system, the present invention proposes the following Figure 2 The method for suppressing current harmonic disturbance of permanent magnet synchronous motor shown in FIG. 1 includes the following specific steps:

[0074] S1: First, establish the stator current equation of the permanent magnet synchronous motor and express it as:

[0075] (1)

[0076] in, Indicates time, represents the d-axis stator current, represents the q-axis stator current, represents the d-axis inductance, Indicates the q-axis inductance. Since the d-axis and q-axis inductances of the surface-mounted permanent magnet synchronous motor are consistent, they can be uniformly expressed as Indicates that , represents the stator resistance, Indicates the number of motor pole pairs, Represents the motor mechanical angular velocity, represents the flux linkage of the permanent magnet.

[0077] Based on the stator current equation of the permanent magnet synchronous motor, the harmonic sources in the motor system are analyzed and calculated, and the periodic current harmonics introduced by various factors are calculated, including:

[0078] Since the permanent magnets of the permanent magnet synchronous motor are not perfect ideal magnets, their magnetic field distribution may be somewhat non-uniform, or during the operation of the motor, due to factors such as armature reaction, magnetic flux harmonics may be generated on the dq axis. Therefore, based on the above stator current equation (1), the magnetic flux harmonics in the d-axis and q-axis directions are derived and calculated, and the permanent magnet magnetic flux harmonics under the dq axis are obtained as:

[0079] (2)

[0080] in, represents the d-axis flux harmonic, represents the q-axis flux harmonic, represents the amplitude of the 6kth harmonic of the d-axis, It represents the amplitude of the 6kth harmonic of the q-axis, where k is an integer. The 6kth harmonic means that the frequency of the harmonic is 6k times the fundamental frequency.

[0081] In inverters, dead time is set to prevent the switches in the upper and lower arms from turning on simultaneously, causing a short circuit. However, the existence of dead time causes the inverter's output PWM waveform to differ from the ideal waveform, generating voltage harmonics. The voltage harmonics caused by the inverter dead time effect can be expressed as:

[0082] (3)

[0083] in, represents the d-axis voltage harmonic, q-axis voltage harmonics, Indicates the dead time, represents the sampling period, Indicates DC voltage.

[0084] The harmonic disturbance of the current loop dq axis is defined as:

[0085] (4)

[0086] in, , represents the harmonic disturbance of dq axis, represents the harmonic disturbance of the d-axis, represents the harmonic disturbance of the q-axis, , represents the dq axis voltage harmonics caused by the inverter dead zone effect, represents the d-axis voltage harmonics caused by the inverter dead zone effect, represents the q-axis voltage harmonics caused by the inverter dead-time effect, , represents the permanent magnet flux harmonics under the dq axis, represents the d-axis flux harmonic, represents the q-axis flux harmonic, , Indicates the number of pole pairs of the motor, is the mechanical angular velocity of the motor, , Indicates the d-axis inductance and the nominal value of the d-axis inductance The error, , Indicates the q-axis inductance and the nominal value of the q-axis inductance The error, .

[0087] Due to the uncertainty and time-varying nature of system parameters, the current loop is also affected by non-periodic disturbances on the dq axis. In the embodiment of the present invention, the non-periodic disturbances on the dq axis of the current loop are defined as:

[0088] (5)

[0089] in, represents the d-axis non-periodic perturbation, represents the q-axis non-periodic disturbance, , Indicates stator resistance With the nominal value of resistance The error, , , , and Represent the nominal inductance values of the d-axis and q-axis respectively, , Indicates the motor flux With the nominal value of magnetic flux The error, represents the d-axis uncertainty disturbance, represents the q-axis uncertainty disturbance.

[0090] Based on the above factors, the d-axis disturbance can be obtained as: ; The q-axis disturbance is: In addition, nonlinear behaviors such as limiting saturation operation will appear in the control system, which will cause the d-axis and q-axis voltages to not match, thus causing non-periodic disturbances. and On the basis of , it is necessary to further consider the non-periodic disturbance introduced by voltage mismatch, and after considering the total disturbance composed of periodic harmonic disturbance and non-periodic disturbance, the mathematical model of the permanent magnet synchronous motor current loop can be rewritten as:

[0091] (6)

[0092] in, represents the current control gain, , represents the d-axis stator reference voltage, represents the q-axis stator reference voltage, represents a known perturbation about the d-axis, , represents a known disturbance on the q-axis , Indicates Based on this, we further consider the total d-axis disturbance caused by voltage mismatch. , Indicates Based on this, we further consider the total q-axis disturbance caused by voltage mismatch. .

[0093] To facilitate the subsequent design of the extended state observer, the dq axis total disturbance is defined as the extended state of the motor system, that is, as one of the state variables. The extended state observer is then used to estimate the total disturbance in real time, thereby compensating for the total disturbance in the control strategy. After defining the dq axis total disturbance as the extended state of the motor system, the obtained extended state system is:

[0094] (7)

[0095] (8)

[0096] in, and is assumed to be differentiable, is the derivative of the total disturbance about the d-axis, is the derivative of the total disturbance about the q axis.

[0097] S2: It should be pointed out that although increasing the bandwidth of the traditional extended state observer can significantly enhance its ability to observe disturbances, it will inevitably amplify the noise and reduce the robustness of the system. In addition, the extended state observer (TRSC-ESO) based on the traditional resonance (TRSC) characteristics has significant advantages in enhancing the observation capability of harmonic disturbances. However, this method often introduces undesirable peak phenomena near the resonant frequency, thereby amplifying the noise in this frequency band and even causing system instability. Therefore, the purpose of the present invention is to design an extended state observer (IRSC-ESO) based on improved resonance (IRSC), which, by optimizing the resonance characteristics and the observer structure, effectively eliminates the undesirable peaks near the resonant frequency while enhancing the ability to suppress harmonic disturbances.

[0098] In order to achieve comprehensive suppression of non-periodic disturbances and periodic harmonic disturbances while avoiding the problem of unexpected peaks, an improved resonant controller (IRSC) is designed for any frequency harmonic. for:

[0099] (9)

[0100] in, represents the resonant gain, represents the resonant bandwidth, represents the resonant frequency, , represents the Laplace complex frequency variable, represents the bandwidth of the extended state observer.

[0101] Due to the existence of multiple harmonic disturbances, in order to effectively suppress multiple harmonic disturbances, it is necessary to promote the function of the improved resonant controller so that it has the ability to suppress multiple frequency harmonic disturbances. Therefore, based on (9), when suppressing multiple frequency harmonic disturbances, the improved resonant controller based on multiple frequencies is extended and promoted. The expression is:

[0102] (10)

[0103] in, Represents the resonance gain at different frequencies, Represents the resonant bandwidth of different frequencies, Indicates the resonant frequencies of different frequencies.

[0104] Considering that the harmonic amplitude decreases with the increase of harmonic order, only the influence of the 6th and 12th harmonic disturbances is considered. For the 6th and 12th harmonic disturbances, an improved resonant controller is designed. for:

[0105] (11)

[0106] in, , .

[0107] According to the mathematical model of the permanent magnet synchronous motor current loop expressed by equation (6), an extended state observer is designed, and the improved resonant controller is embedded in the extended state observer. The improved resonant-extended state observers of the d-axis and q-axis are obtained as follows:

[0108] (12)

[0109] (13)

[0110] in, represents the d-axis stator current estimate, represents the q-axis stator current estimate, represents the total disturbance estimate of the d-axis, represents the total disturbance estimate of the q-axis, represents the d-axis non-periodic perturbation estimate, represents the q-axis non-periodic disturbance estimate, represents the d-axis harmonic disturbance estimate, represents the q-axis harmonic disturbance estimate, 、 、 and is the state variable of the improved resonant controller, and is the gain coefficient of the extended state observer, and Represents an intermediate variable.

[0111] Furthermore, according to the pole placement strategy, the characteristic equation satisfies The gain coefficient of the n-order extended state observer is:

[0112] (14)

[0113] in, , is defined as the observer bandwidth. Therefore, the gain coefficient of the extended state observer based on improved resonance can be deduced as .

[0114] S3: If Figure 3As shown in Figure 1, the total disturbance obtained by the resonant-extended state observer in S2 is introduced into the control end as a feedforward signal, and a reasonable control law is designed to realize the enhanced active disturbance rejection control based on the improved resonant-extended state observer, and the observed disturbance signal is accurately suppressed and eliminated, thereby further enhancing the control accuracy and robustness of the system. Specifically, the d-axis reference current and q-axis reference current ,definition , , we can get:

[0115] (15)

[0116] Using proportional control, the error convergence control law can be expressed as:

[0117] (16)

[0118] in, and are the d-axis and q-axis current loop controller gains respectively.

[0119] Substituting formula (16) into formula (15) yields:

[0120] (17)

[0121] In Equation (17), the total disturbance is unknown, and the observed value is usually used instead of the actual value. In addition, to reduce the influence of measurement noise, the current estimated by the observer is used instead of the actual current. The control law can then be rewritten as:

[0122] (18)

[0123] in, , , 、 It is the total disturbance estimate obtained by S2 observation, which can realize the compensation of unknown disturbance, referring to the differential feedforward 、 It is used to reduce the oscillation and overshoot phenomena in the dynamic process of the system, and significantly shorten the adjustment time of the system.

[0124] If all disturbances can be accurately compensated, the dq-axis system can be simplified to an integrator, that is:

[0125] (19)

[0126] Furthermore, to verify the superiority of the improved resonant-extended state observer, the present invention conducted comparative experiments on a traditional resonant controller (ESO), an extended state observer based on traditional resonance (TRSC) characteristics (TRSC-ESO), and a resonant-extended state observer based on improved resonance (IRSC) (IRSC-ESO). The results are as follows:

[0127] Figure 4 and Figure 5 They were shown From 2rad / s to 30rad / s, The Bode plot of a traditional quasi-resonant controller when the value changes from 10 to 120. The horizontal axis is the frequency (in rad / s), and the vertical axis is the resonance amplitude (in dB).

[0128] Figure 6 and Figure 7 Shown respectively in From 2rad / s to 30rad / s, Bode plot of the improved resonant controller when varying from 10 to 120, using bandwidth The horizontal axis is the frequency (Frequency), the unit is rad / s, and the vertical axis is the resonance amplitude (Magnitude), the unit is dB.

[0129] Depend on Figures 4 to 7 It can be seen that both the improved resonant controller and the traditional quasi-resonant controller exhibit significant amplitude peaks at the resonant frequency. This characteristic plays a key role in suppressing harmonic disturbances of the target frequency. Parameters can significantly broaden the resonance bandwidth, thereby improving the system's robustness to changes in the resonance frequency; and increasing the resonance gain This further enhances the suppression performance of both controllers at the target resonant frequency, effectively enhancing the system's harmonic suppression. However, there are significant differences in the amplitude-frequency response characteristics of the two controllers outside the resonant frequency: the traditional quasi-resonant controller exhibits a typical -20dB / dec amplitude-frequency attenuation characteristic outside the resonant frequency, while the improved resonant controller can maintain a 0dB amplitude-frequency response outside the resonant frequency.

[0130] Furthermore, in order to illustrate and verify the superiority of using the improved resonant-extended state observer to estimate and compensate for the total disturbance, the mathematical model of the permanent magnet synchronous motor current loop and the resonant-extended state observer considering the total disturbance are analyzed. When , the transfer function between the disturbance estimation error of the traditional extended state observer and the actual disturbance can be obtained for:

[0131] (20)

[0132] in, represents the actual disturbance signal, represents the disturbance estimate obtained by the traditional extended state observer, , .

[0133] Similarly, the transfer function between the disturbance estimation error and the actual disturbance based on the traditional resonant extended state observer can be derived: for:

[0134] (twenty one)

[0135] in, represents the actual disturbance signal, represents the disturbance estimate obtained based on the traditional resonant-extended state observer, , .

[0136] Transfer function between disturbance estimation error and actual disturbance based on improved resonant-extended state observer for:

[0137] (twenty two)

[0138] in, represents the actual disturbance signal, represents the total disturbance estimate obtained by the improved resonant-extended state observer, .

[0139] From this, we can draw 、 and Bird Figure 8 As shown, where the bandwidth 100rad / s, resonance bandwidth , resonant frequency 、 The resonance gain of TRSCs and the resonance gain of IRSCs are 400 rad / s and 1000 rad / s respectively. .

[0140] from Figure 8It can be seen that the amplitude-frequency characteristics and phase-frequency characteristics of ESO, TRSC-ESO and IRSC-ESO in the low and high frequency bands are relatively small, indicating that the three have similar performance in these frequency bands. In addition, both TRSC-ESO and IRSC-ESO show significant amplitude attenuation at the resonant frequency. This large amplitude attenuation characteristic enables the observer to accurately estimate the harmonic interference of the same frequency and exhibits excellent frequency selectivity. However, from Figure 8 It can also be found that the extended state observer based on traditional resonance has an undesirable peak phenomenon near the resonant frequency, that is, the amplitude-frequency response exceeds 0dB in some frequency ranges. Compared with the traditional extended state observer, this peak phenomenon will amplify the interference estimation error, thereby reducing the estimation effect of the actual interference, thereby affecting the performance of the observer in practical applications. In contrast, the extended state observer based on improved resonance has successfully eliminated the undesirable peak phenomenon near the resonant frequency through optimized design. In addition, it requires a lower resonant gain to achieve the same harmonic suppression performance. In summary, under the same bandwidth conditions, the invented extended state observer based on improved resonance not only effectively eliminates the negative impact of the undesirable peak in the traditional resonant observer, but also exhibits stronger harmonic suppression performance, reflecting superior control performance.

[0141] Furthermore, to illustrate and verify the advancement of the enhanced active disturbance rejection control (EADRC) based on the improved resonant-extended state observer, a comparative analysis is conducted among the traditional active disturbance rejection control (ADRC) based on the extended state observer, the improved active disturbance rejection control (IADRC) based on the traditional resonant-extended state observer, and the enhanced active disturbance rejection control (EADRC) based on the improved resonant-extended state observer as follows:

[0142] Based on the permanent magnet synchronous motor current loop mathematical model, resonant-extended state observer and control law considering the total disturbance, When , we can get the transfer function of ADRC output under disturbance for:

[0143] (twenty three)

[0144] Similarly, the closed-loop system output transfer function of IADRC under disturbance can be derived: for:

[0145] (twenty four)

[0146] The output transfer function of the EADRC closed-loop system under disturbance is derived. for:

[0147] (25)

[0148] Draw 、 and Bird Figure 9 As shown, where the bandwidth 100rad / s, resonance bandwidth , resonant frequency 、 The resonant gain of TRSCs is 400 rad / s and 1000 rad / s respectively. , the resonant gain of IRSCs .from Figure 9 Frequency domain characteristic analysis shows that the three active disturbance rejection controllers exhibit similar performance in both low- and high-frequency ranges. Furthermore, both IADRC and EADRC exhibit significant amplitude attenuation at the resonant frequency, giving them a significant advantage in suppressing harmonic interference. Notably, EADRC avoids undesirable peaks near the resonant frequency, improving closed-loop system stability.

[0149] Figure 10 The waveforms of the dq axis and phase currents of the permanent magnet synchronous motor under the traditional active disturbance rejection control at 150 r / min and 3 N·m are shown in Figure 1. , It can be seen that the q-axis current ripple peak value of the traditional active disturbance rejection control is 0.625A, the d-axis current ripple peak value is 0.336A, and the q-axis current total harmonic distortion is 7.12%. The horizontal axis is frequency (Hz), and the vertical axis is current amplitude (A).

[0150] Figure 11 The waveforms of the dq axis and phase currents of the permanent magnet synchronous motor under the traditional resonant auto-disturbance rejection control at 150 r / min and 3 N·m are shown in the figure. , , , , , , It can be clearly seen that the q-axis current ripple peak of the traditional resonant ADRC is 0.346A, the d-axis current ripple peak is 0.252A, and the q-axis current total harmonic distortion is 2.57%, indicating that the traditional resonant ADRC has good harmonic suppression capabilities. However, fast Fourier transform (FFT) analysis shows that the traditional resonant ADRC introduces an undesirable peak amplification effect near the resonant frequency, especially for the 15th and 18th harmonics. This peaking effect not only increases higher-order harmonics but also amplifies the impact of noise, resulting in reduced system stability and thus restricting the performance optimization of the control system.

[0151] Figure 12 Figure 2 is the waveform of the dq axis and phase current of the permanent magnet synchronous motor under the proposed enhanced active disturbance rejection control at 150 r / min and 3 N·m. , , , , It can be clearly seen that the q-axis current pulsation peak value of the enhanced active disturbance rejection control is 0.187A, the d-axis current pulsation peak value is 0.125A, and the q-axis current total harmonic distortion is 1.64%. By comparison Figure 10 It can be found that the invented enhanced active disturbance rejection control method shows significant advantages in suppressing periodic harmonics and effectively reduces the impact of harmonics on system performance. Figure 11 It can be seen that compared to traditional resonant ADRC, the enhanced ADRC requires a smaller resonant gain. Despite the smaller gain, the enhanced ADRC still outperforms traditional resonant ADRC in harmonic suppression and effectively overcomes the undesirable peaking problem common in traditional control methods. Specifically, the enhanced ADRC suppresses the target harmonic while avoiding amplifying harmonics and noise at nearby frequencies, significantly improving system stability. Furthermore, thanks to its wide bandwidth design, the enhanced ADRC also reduces the amplitude of the 15th and 18th harmonics. This feature further improves the quality of the motor current and reduces the interference of harmonics on motor smoothness, thereby providing better assurance for high-performance system operation.

[0152] Figure 13 The d-axis and q-axis current waveforms of the permanent magnet synchronous motor when the inductance changes under the working conditions of 150rad / s and 6N·m. It can be clearly observed that when the d-axis and q-axis inductances are mismatched at the same time, the system d-axis current fluctuates significantly. However, thanks to the excellent disturbance suppression capability of the controller, this fluctuation can be quickly attenuated and restored to a steady state. In addition, from the total harmonic distortion (THD) analysis of the current, it can be seen that the THD before and after the inductance parameter changes are basically consistent, indicating that the system performance is not significantly affected. Similar system dynamic behaviors under resistance and flux linkage mismatch are also respectively Figure 14 and Figure 15 These results show that the designed control strategy can effectively resist the adverse effects of parameter changes under complex working conditions, ensuring that the system has strong anti-interference performance and reliability.

[0153] As a result, the invented enhanced ADRC demonstrates stronger harmonic suppression capabilities compared to traditional ADRC and traditional resonant ADRC, successfully resolving the undesirable peaking problem inherent in traditional resonant ADRC algorithms. Furthermore, the method exhibits strong parameter robustness, maintaining excellent control performance despite system parameter variations.

[0154] In short, the above description is only a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this specification shall be included in the scope of protection of this specification.

[0155] The systems, devices, modules, or units described in one or more of the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0156] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0157] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0158] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for suppressing current harmonic disturbances of a permanent magnet synchronous motor, characterized in that: include: A mathematical model of the permanent magnet synchronous motor current loop considering the total disturbance is constructed, and the total disturbance of the dq axis is defined as the expansion state of the motor system; the mathematical model of the permanent magnet synchronous motor current loop considering the total disturbance is: ； in, Indicates time, represents the d-axis stator current, represents the q-axis stator current, represents the current control gain, , Indicates the nominal value of the motor’s inductance, represents the d-axis stator reference voltage, represents the q-axis stator reference voltage, represents a known perturbation about the d-axis, represents a known disturbance on the q-axis, represents the total disturbance on the d-axis, represents the total disturbance on the q-axis; Design an improved resonant controller for any frequency harmonics for: ； in, represents the resonant gain, represents the resonant bandwidth, represents the resonant frequency, , represents the Laplace complex frequency variable, represents the bandwidth of the extended state observer; and embedding the improved resonant controller into an extended state observer to estimate the total disturbance; The total disturbance estimation is introduced into the control end as a feedforward signal, and the control law is designed to compensate the total disturbance in the mathematical model of the permanent magnet synchronous motor current loop.

2. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 1, characterized in that: The total disturbance includes: non-periodic disturbance and periodic harmonic disturbance.

3. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 2, characterized in that: The calculation formula for the harmonic disturbance of the current loop dq axis is: ； in, , represents the harmonic disturbance of dq axis, represents the harmonic disturbance of the d-axis, represents the harmonic disturbance of the q-axis, , represents the dq axis voltage harmonics caused by the inverter dead zone effect, represents the d-axis voltage harmonics caused by the inverter dead zone effect, represents the q-axis voltage harmonics caused by the inverter dead-time effect, , represents the permanent magnet flux harmonics under the dq axis, represents the d-axis flux harmonic, represents the q-axis flux harmonic, , Indicates the number of pole pairs of the motor, is the mechanical angular velocity of the motor, , Indicates the d-axis inductance and the nominal value of the d-axis inductance The error, , Indicates the q-axis inductance and the nominal value of the q-axis inductance The surface-mounted permanent magnet synchronous motor meets the error of ; The calculation formula for the non-periodic disturbance of the current loop dq axis is: ； in, Indicates the non-periodic disturbance of the current loop d-axis, Indicates the non-periodic disturbance of the current loop q axis, , Indicates stator resistance With the nominal value of resistance The error, Indicates the motor flux With the nominal value of magnetic flux The error, represents the d-axis uncertainty disturbance, represents the q-axis uncertainty disturbance.

4. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 3, characterized in that: The total disturbance of the dq axis is defined as the expanded state of the motor system, and the expanded state system is obtained as: ； ； in, is the derivative of the total disturbance about the d-axis, is the derivative of the total disturbance about the q axis.

5. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 3, characterized in that: Improved resonant controller for suppressing multi-frequency harmonic disturbances The expression is: ； in, Represents the resonance gain at different frequencies, Represents the resonant bandwidth of different frequencies, Indicates the resonant frequencies of different frequencies.

6. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 5, characterized in that: Suppress the 6th harmonic disturbance and the 12th harmonic disturbance. , .

7. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 6, characterized in that: The improved resonant controller is embedded in the extended state observer to obtain the improved d-axis and q-axis resonant-extended state observer: ； ； in, represents the d-axis stator current estimate, represents the q-axis stator current estimate, represents the total disturbance estimate of the d-axis, represents the total disturbance estimate of the q-axis, represents the d-axis non-periodic perturbation estimate, represents the q-axis non-periodic disturbance estimate, represents the d-axis harmonic disturbance estimate, represents the q-axis harmonic disturbance estimate, 、 、 and is the state variable of the improved resonant controller, and is the gain coefficient of the extended state observer, and is an intermediate variable.

8. The method for suppressing current harmonic disturbance of a permanent magnet synchronous motor according to claim 7, characterized in that: The control law is: ； in, represents the d-axis stator reference voltage, represents the q-axis stator reference voltage, represents the d-axis reference current, represents the q-axis reference current, is a constant used to compensate for known disturbances in the d-axis. is a constant used to compensate for the known disturbance on the q axis. , represents the d-axis current loop controller gain, , Represents the q-axis current loop controller gain.

9. A motor system, characterized in that: A method for suppressing current harmonic disturbances of a permanent magnet synchronous motor as described in any one of claims 1 to 8 is adopted.

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