Permanent magnet synchronous motor current disturbance suppression method based on repetitive improved ADRC

Abstract

The application discloses a permanent magnet synchronous motor current disturbance suppression method based on a repetitive improved ADRC, and belongs to the technical field of motor control. The specific method comprises the following steps: embedding a repetitive controller into an extended state observer, connecting the repetitive controller in parallel with a disturbance observation part of the extended state observer, and forming a new repetitive extended state observer. The repetitive extended state observer utilizes the repetitive controller to perform high-precision estimation on periodic disturbance, utilizes the extended state observer to perform real-time estimation on non-periodic disturbance, and obtains a total disturbance estimation value in cooperation. The total disturbance estimation value is fed back to a feedback control law in real time, a shaft voltage reference value is generated dq A control signal is obtained through coordinate transformation according to the voltage reference value, and the permanent magnet synchronous motor is controlled according to the control signal.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and more specifically to an application method of ADRC based on repetitive control in suppressing current loop disturbances in permanent magnet synchronous motors. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in industrial control due to their high efficiency and power density. Nonlinear characteristics such as inverter dead time and device voltage drops are prevalent in PMSM drive systems. Traditional active disturbance rejection controllers (ADRCs) cannot effectively suppress these periodic disturbances, leading to motor current distortion. Furthermore, non-periodic disturbances such as load abrupt changes and parameter perturbations also occur during motor operation. The presence of harmonic currents and various disturbances increases motor torque, speed fluctuations, and losses, degrading system control performance. Domestic and international scholars have conducted extensive research on how to effectively suppress motor current harmonics and disturbances. Two main methods for current harmonic suppression have been adopted: one focuses on motor design, optimizing the motor structure and improving the distribution of the permanent magnet's magnetic field, but this method requires high machining precision and is difficult to implement; the other focuses on suppressing current harmonics from a control perspective. Traditional ADRCs utilize extended state observers (ESOs) to estimate and compensate for the total system disturbance in real time, demonstrating good suppression capabilities for non-periodic disturbances such as load abrupt changes.

[0003] However, due to the limited bandwidth of the ESO, traditional ADRC cannot perform error-free tracking and suppression of periodic disturbance signals, thus making it difficult to effectively suppress periodic current harmonics caused by inverter dead-time effects. Therefore, improving ADRC by introducing a controller is the mainstream research approach today. A repetitive controller based on the internal model principle, through proper design, can achieve precise suppression of specific integer multiples of harmonic disturbances, enhancing the steady-state response quality of the current loop. Summary of the Invention

[0004] To address the aforementioned issues, this paper proposes an application method for repetitive active disturbance rejection control (ADRC) based on repetitive control in suppressing current loop disturbances in permanent magnet synchronous motors. This method primarily improves the ESO structure in traditional ADRC by connecting the repetitive controller and the disturbance estimation component in the ESO in parallel to form a new repetitive extended state observer. This new observer, together with the feedback control law, forms a new repetitive active disturbance rejection control (RC-ADRC). The proposed invention estimates periodic disturbances using the repetitive controller and non-periodic disturbances using the built-in components of the ESO. The sum of these estimates is fed back to the feedback control law as the total disturbance for suppression, thus solving the problem of insufficient periodic disturbance suppression capability in traditional ADRC.

[0005] This optimization strategy effectively suppresses various disturbances in the current loop. The method effectively suppresses harmonic distortion in the control current, significantly improves the steady-state performance of the motor control system, and enhances the overall stability and efficiency of the system.

[0006] The technical means employed in this invention are as follows: This invention provides a method for applying repetitive control-based ADRC in suppressing current loop disturbances in permanent magnet synchronous motors, including: In the extended state observer of the permanent magnet synchronous motor current loop, a repetitive controller is embedded and forms a parallel structure with the disturbance observation part of the extended state observer; A repetitive controller is used to make high-precision estimates of the periodic disturbances caused by inverter dead zone effect and flux harmonics, and an extended state observer is used to make real-time estimates of the non-periodic disturbances caused by load change and parameter perturbation. The total disturbance estimate is obtained by summing the periodic disturbance estimate of the repetitive controller with the aperiodic disturbance estimate of the extended state observer. The total disturbance estimate is fed back as a feedback signal to the feedback control law to obtain the voltage reference value. The voltage reference value is then transformed into a coordinate to obtain the control signal. The permanent magnet synchronous motor is controlled according to the control signal.

[0007] Furthermore, embedding the repetitive controller into the extended state observer and forming a parallel structure with the disturbance observation part includes: The three-phase current of the permanent magnet synchronous motor is sampled, and the torque current and excitation current are obtained by decoupling coordinate transformation of the three-phase current; Set the excitation current to 0 and establish a mathematical model of the permanent magnet synchronous motor; According to the mathematical model of the permanent magnet synchronous motor, the permanent magnet synchronous motor has 6k periodic disturbances and non-periodic disturbances. The extended state observer is used to estimate aperiodic disturbances, and the repetitive controller is used to estimate 6k periodic disturbances. The two are connected in parallel to output the total disturbance estimate.

[0008] Furthermore, the mathematical model for establishing the current loop and its disturbance of the permanent magnet synchronous motor is calculated in the following manner:

[0009] In the formula: They are respectively dq shaft current, They are respectively dq shaft voltage, They are respectively dq Shaft inductor, R The resistance of the stator winding, The electric angular velocity of the rotor, It is the magnetic flux of a permanent magnet.

[0010]

[0011] In the formula: They are respectively dq Magnetic flux of axial permanent magnet.

[0012]

[0013] In the formula: and They are respectively dq Shaft voltage harmonics, and The values ​​are sampling time, dead time, and DC bus voltage, respectively. It can be seen that the inverter dead time effect causes an additional six-fold fundamental harmonic component in the voltage switching signal output by the FOC strategy.

[0014] As a further aspect of the present invention: designing an extended state observer in ADRC.

[0015] As a further aspect of the present invention: design the parallel repetitive controller including a low-pass filter and a phase compensator.

[0016] As a further aspect of the present invention: an extended state observer is designed with a parallel repetitive controller in the disturbance observation section. The disturbance observation module of the conventional ESO observes the non-periodic disturbances, and the parallel repetitive controller observes the periodic disturbances caused by the inverter dead zone effect and flux harmonics. The sum of the observations is the estimated value of the total disturbance.

[0017] As a further aspect of the present invention: the total disturbance estimate is fed back into the control law, and the control law of the proposed method is designed.

[0018] Compared with the prior art, the present invention has the following advantages: The present invention provides a method for applying repetitive ADRC based on repetitive control to suppress current loop disturbances in permanent magnet synchronous motors. The method includes: embedding a repetitive controller into an extended state observer, connecting it in parallel with the disturbance observation part of the extended state observer to form a new repetitive extended state observer. This repetitive extended state observer utilizes the repetitive controller to perform high-precision estimation of periodic disturbances and utilizes the extended state observer to perform real-time estimation of aperiodic disturbances; the two work together to obtain a total disturbance estimate. The obtained total disturbance estimate is fed back to the feedback control law in real time to generate... dqShaft voltage reference value. A coordinate transformation is performed based on the voltage reference value to obtain the control signal, which controls the permanent magnet synchronous motor. An extended state observer is embedded in the repetitive controller and connected in parallel with the disturbance observation section, compensating for the lack of periodic disturbance suppression capability in traditional active disturbance rejection controllers while retaining the ability to suppress aperiodic disturbances. This achieves coordinated suppression of periodic and aperiodic disturbances in the current loop, improving three-phase current accuracy, reducing stator current harmonic content, and improving the motor's output electromagnetic torque. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This invention provides a method for suppressing current disturbances in permanent magnet synchronous motors based on repetitive improved ADRC. Figure 2 A block diagram of the repetitive controller structure provided by the present invention; Figure 3 The current loop RC-ADRC structure block diagram provided by the present invention; Figure 4 The disturbance amplitude-frequency curve of the current closed-loop system provided by this invention; Figure 5 A graph showing the speed comparison results between the method of this invention and the PI controller provided by this invention; Figure 6 A comparison diagram of three-phase currents based on the method of this invention and a traditional active disturbance rejection controller is provided for this invention. Figure 7 A comparison diagram of the q-axis current based on the method of this invention and the traditional active disturbance rejection controller is provided for this invention; Figure 8 A schematic diagram of q-axis current Fourier harmonic analysis based on the method of this invention and a traditional active disturbance rejection controller, provided for the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] like Figure 1 The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC, as shown, includes: In the extended state observer of the permanent magnet synchronous motor current loop, a repetitive controller is embedded and forms a parallel structure with the disturbance observation part of the extended state observer; A repetitive controller is used to make high-precision estimates of the periodic disturbances caused by inverter dead zone effect and flux harmonics, and an extended state observer is used to make real-time estimates of the non-periodic disturbances caused by load change and parameter perturbation. The total disturbance estimate is obtained by summing the periodic disturbance estimate of the repetitive controller with the aperiodic disturbance estimate of the extended state observer. The total disturbance estimate is fed back as a feedback signal to the feedback control law to obtain the voltage reference value. The voltage reference value is then transformed into a coordinate to obtain the control signal. The permanent magnet synchronous motor is controlled according to the control signal.

[0024] Nonlinear characteristics such as inverter dead time and device voltage drop are prevalent in permanent magnet motor drive systems. While traditional Advanced Dynamic Range (ADRC) systems offer good suppression of aperiodic disturbances like load abrupt changes, they lack internal model support and cannot effectively suppress periodic disturbances. This leads to motor current distortion, and the presence of harmonic currents increases motor torque, speed fluctuations, and losses, degrading system control performance. This invention embeds a repetitive controller into an extended state observer (ESO), forming a parallel structure with the ESO's disturbance observation section. The repetitive controller provides high-precision estimation of periodic disturbances, while the extended state observer provides real-time estimation of aperiodic disturbances. The two work together to achieve comprehensive suppression of both periodic and aperiodic disturbances, overcoming the deficiency of traditional ADRC in suppressing periodic disturbances. This improves three-phase current accuracy, reduces stator current harmonic content, and enhances motor output electromagnetic torque. Embedding the repetitive controller within the extended state observer allows for structural parallel connection between the repetitive controller and the ESO's disturbance observation section, sharing input signals and facilitating coordinated observation of periodic and aperiodic components at the disturbance estimation level. Specifically, refer to Figure 1 The total disturbance estimate is fed back to the feedback control law to obtain the voltage reference value. After the voltage reference value is transformed by coordinates, it is modulated into a control signal by the space vector modulation module to realize the control of the three-phase permanent magnet synchronous motor.

[0025] Furthermore, embedding the repetitive controller into the extended state observer and forming a parallel structure with the disturbance observation part includes: The three-phase current of the permanent magnet synchronous motor is sampled, and the torque current and excitation current are obtained by decoupling coordinate transformation of the three-phase current; Set the excitation current to 0 and establish a mathematical model of the permanent magnet synchronous motor; According to the mathematical model of the permanent magnet synchronous motor, the permanent magnet synchronous motor has 6k periodic disturbances and non-periodic disturbances. The extended state observer is used to estimate aperiodic disturbances, and the repetitive controller is used to estimate 6k periodic disturbances. The two are connected in parallel to output the total disturbance estimate.

[0026] Furthermore, a mathematical model of the current loop and its disturbance of the permanent magnet synchronous motor is established, and calculated in the following manner:

[0027] In the formula: They are respectively dq shaft current, They are respectively dq shaft voltage, They are respectively dq Shaft inductor, R The resistance of the stator winding, The electric angular velocity of the rotor, It is the magnetic flux of a permanent magnet.

[0028]

[0029] In the formula: They are respectively dq Magnetic flux of axial permanent magnet.

[0030]

[0031] In the formula: and They are respectively dq Shaft voltage harmonics, and The values ​​are sampling time, dead time, and DC bus voltage, respectively. It can be seen that the inverter dead time effect causes an additional six-fold fundamental harmonic component in the voltage switching signal output by the FOC strategy.

[0032] Furthermore, the extended state observer is designed as follows:

[0033] In the formula, f This represents the total disturbance of the current loop. For parameters b The calibration value. The total disturbance. f Expand to new state variables, the expanded state equation is:

[0034] In the formula: For total disturbance f The differential value of is bounded. According to the extended state equation, the ESO in ADRC can be designed as

[0035] In the formula, the state variable marked with the symbol "^" is the estimated value of its corresponding variable. and This is the gain of the ESO. It is calculated as follows:

[0036] Furthermore, the repetitive controller includes a low-pass filter and a phase compensator, the mathematical structure of which is as follows:

[0037] In the formula: For the repetitive controller gain, For the delayed phase, N This is the ratio of the fundamental period of the disturbance current to the system sampling period. Q(z) It is a low-pass filter. C(z) For phase compensators, Sampling frequency, The harmonic frequency is used. The low-pass filter is designed as follows:

[0038] The phase compensator is designed to be

[0039] Furthermore, the mathematical structure of the repetitive controller embedding the extended state observer is as follows:

[0040] In the formula, It is a non-periodic disturbance. It is a periodic disturbance.

[0041] Specifically, such as Figure 4 The curves represent the disturbance transfer amplitude-frequency characteristics of ADRC and RC-ADRC, respectively. Comparing the two curves, it can be seen that RC-ADRC has a better suppression effect on the sixth harmonic and its integer multiples of the fundamental frequency, based on ADRC.

[0042] Furthermore, the total disturbance estimate is fed back into the feedback control law to obtain the voltage reference value, which is calculated as follows:

[0043] In the formula For the control law bandwidth, Its magnitude directly determines the speed of the current dynamic response.

[0044] In the simulation experiment, the initial motor speed was designed to be 500 rpm, which jumped to 1000 rpm in 1.5 seconds, and a load torque of 3.35 Nm was applied in 2.5 seconds. This simulation model addresses the non-periodic disturbances encountered by the motor during actual operation, such as speed changes and sudden load changes. It also considers the inherent periodic disturbances caused by inverter dead-time effects and flux harmonics, thus comprehensively examining the disturbance suppression performance of the method described in this invention. The following is a continuation of this analysis. Figures 5 to 8 A detailed analysis of the simulation results is conducted.

[0045] Figure 5A comparison of speed waveforms based on the method of this invention and a PI controller is provided for this invention. As can be seen from the figure, the method of this invention can handle large speed jumps and exhibits good dynamic performance. When a load torque of 3.35 Nm is suddenly applied at 2.5 s, the speed under the PI controller shows a significant drop. In contrast, the speed drop of the method of this invention is significantly smaller than that of the PI controller at the moment of load sudden application. This result indicates that the method of this invention, through the extended state observer, performs real-time estimation and compensation for aperiodic disturbances such as load abrupt changes, fully preserving the suppression capability of traditional ADRC for aperiodic disturbances, enabling the system to maintain good speed tracking performance under both speed jump and load abrupt changes conditions.

[0046] Figure 6 (a) Figure Figure 6 (b) The figures show a comparison of the three-phase current waveforms of the traditional active disturbance rejection controller (ADRC) and the method proposed in this invention. As can be seen from the figures, the three-phase current waveform under the traditional ADRC control exhibits significant distortion and poor waveform smoothness. In contrast, the three-phase current waveform under the control method of this invention is smooth, sinusoidal, and exhibits no significant distortion, verifying the suppression effect of the method of this invention on periodic disturbances.

[0047] Figure 7 The steady-state q-axis current waveforms based on the method of this invention are compared with those of a traditional active disturbance rejection controller (ADRC). The figures clearly show that the q-axis current under traditional ADRC control exhibits significant steady-state ripple, with noticeable current fluctuations. In contrast, the steady-state ripple of the q-axis current under the control of the method of this invention is significantly reduced, the current waveform is more stable, and the ripple amplitude is significantly smaller than that of traditional ADRC. This indicates that the method of this invention, by connecting the repetitive controller in parallel with the ESO, effectively observes and compensates for periodic disturbances at the disturbance estimation level, thereby significantly reducing the steady-state fluctuations of the torque current and improving the output torque quality of the motor.

[0048] Figure 8 (a) Figure Figure 8 (b) Figures show the q-axis current Fourier harmonic analysis of the traditional active disturbance rejection controller (ADRC) and the method proposed in this invention, respectively. The harmonic suppression effect of the two methods is further quantitatively analyzed from a frequency domain perspective. As can be seen from the comparison of the harmonic histograms in the figures, the content of the 6th, 12th, and 18th harmonics in the method of this invention is significantly lower than that of the traditional ADRC. Quantitatively, the total harmonic distortion rate of the q-axis current under the control of the traditional ADRC is 0.65%, while the total harmonic distortion rate under the control of the method of this invention is reduced to 0.1%, a reduction of 84.6%. This result demonstrates that the RC-ADRC method proposed in this invention can comprehensively and effectively suppress periodic harmonic currents caused by inverter dead-zone effects and flux linkage harmonics, significantly reducing the current harmonic content.

[0049] comprehensive Figures 5 to 8 The simulation results show that the current loop disturbance suppression method for permanent magnet synchronous motors based on RC-ADRC provided by this invention has the following advantages: while retaining the ability of traditional ADRC to suppress aperiodic disturbances, it compensates for the deficiency of traditional ADRC in suppressing periodic disturbances by embedding the repetitive controller into the extended state observer, thus achieving synergistic suppression of periodic and aperiodic disturbances; it significantly reduces steady-state current pulsation and harmonic distortion rate, and improves the sinusoidality of three-phase current and the smoothness of torque output; it exhibits good dynamic response performance under speed step and load change conditions.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC, characterized in that, include: The repetitive controller is embedded in the extended state observer and connected in parallel with the disturbance observation part of the extended state observer to form a repetitive extended state observer. The repetitive extended state observer uses the repetitive controller to make high-precision estimates of periodic disturbances and uses the extended state observer to make real-time estimates of non-periodic disturbances. The two work together to obtain the total disturbance estimate. The obtained total disturbance estimate is fed back to the feedback control law in real time to generate... dq The axis voltage reference value is used to obtain the control signal by performing coordinate transformation based on the voltage reference value. The permanent magnet synchronous motor is controlled according to the control signal.

2. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC as described in claim 1, characterized in that: Embedding the repetitive controller into the extended state observer and forming a parallel structure with the disturbance observation part includes: The three-phase current of the permanent magnet synchronous motor is sampled, and the torque current and excitation current are obtained by decoupling coordinate transformation of the three-phase current; Set the excitation current to 0 and establish a mathematical model of the permanent magnet synchronous motor; Based on the mathematical model of the permanent magnet synchronous motor, it is found that the permanent magnet synchronous motor has 6... k Sub-periodic and non-periodic disturbances; The extended state observer is used to estimate aperiodic disturbances, and the repetitive controller is used to estimate 6 k The two periodic disturbances are connected in parallel to output the total disturbance estimate.

3. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC as described in claim 2, characterized in that: The mathematical model of the permanent magnet synchronous motor is represented as follows: In the formula: They are respectively dq shaft current, They are respectively dq shaft voltage, They are respectively dq Shaft inductor, R The resistance of the stator winding, The electric angular velocity of the rotor, It is the magnetic flux of a permanent magnet. In the formula: They are respectively dq Magnetic flux of axial permanent magnet. In the formula: and They are respectively dq Shaft voltage harmonics, and These represent the sampling time, dead time, and DC bus voltage, respectively.

4. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC as described in claim 1, characterized in that: The extended state observer is represented as follows: In the formula, the state variable marked with the symbol "^" is the estimated value of its corresponding variable. and This represents the gain of ESO.

5. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC according to claim 1, characterized in that: The repeat controller is represented as follows: In the formula: For the repetitive controller gain, For the delayed phase, N This is the ratio of the fundamental period of the disturbance current to the system sampling period. Q(z) It is a low-pass filter. C(z) For phase compensators, Sampling frequency, It represents the harmonic frequency.

6. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC according to claim 1, characterized in that: The repeating expansion state observer is designed as follows: In the formula, It is a non-periodic disturbance. It is a periodic disturbance.

7. The method for suppressing current disturbances in a permanent magnet synchronous motor based on repetitive improved ADRC as described in claim 1, characterized in that: The feedback control law is designed as follows: In the formula For the control law bandwidth, Its magnitude directly determines the dynamic response speed of the current.

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