A speed loop linear active disturbance rejection control method and system for permanent magnet synchronous motor

Abstract

The application belongs to the technical field of permanent magnet synchronous motors, and discloses a speed loop linear active disturbance rejection control method and system for a permanent magnet synchronous motor, which is controlled by using an improved linear active disturbance rejection controller; the improved linear active disturbance rejection controller takes a proportional-integral-derivative structure and a repetitive controller as a first linear extended state observer, and takes a traditional linear extended state observer as a second observer for cascading; finally, the total disturbance estimated by the cascaded decoupling repetitive control linear extended state observer is introduced into the control law of the improved linear active disturbance rejection controller to generate a final control quantity for acting on the speed loop and controlling the speed of the permanent magnet synchronous motor. The application can realize separate control of dynamic response speed and disturbance rejection capability, enhance the suppression capability of the linear active disturbance rejection controller on high-frequency periodic disturbance, and improve the suppression capability of the linear active disturbance rejection controller on high-order disturbance.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet synchronous motor technology, specifically relating to a speed loop linear active disturbance rejection control method and system for a permanent magnet synchronous motor. Background Technology

[0002] Traditional linear active disturbance rejection controllers (LESOs) suffer from the following problems: Parameter coupling: The traditional LESO (Linear Extended State Observer) can be equivalent to a second-order low-pass filter in the frequency domain, resulting in inherent errors in high-frequency disturbance estimation. Simply increasing the observer bandwidth introduces noise and affects system stability. The coupling between the controller bandwidth and the observer bandwidth leads to a contradiction between the system's disturbance estimation accuracy and estimation speed, increasing the difficulty of parameter tuning. Insufficient periodic disturbance suppression capability: In practical applications, traditional LESOs are limited by bandwidth, resulting in theoretical deficiencies in their ability to suppress high-frequency periodic disturbances. Lack of high-order disturbance suppression capability: When faced with high-order disturbances, the disturbance estimation error of traditional LESOs will fail to converge to a stable value.

[0003] Chinese patent publication number CN115296586A, entitled "An Improved Linear Active Disturbance Rejection Motor Control Method Based on a Quasi-Resonant Controller," describes a control method comprising: first, establishing a mathematical model of the AC motor current loop and expanding the total disturbance of the current loop into a new state variable; constructing a linear extended state observer and analyzing its frequency domain characteristics; switching the disturbance feedforward channel of the linear extended state observer to expand its observation bandwidth and adding a low-pass filter in the error feedback channel to suppress high-frequency noise in the observation system; connecting a quasi-resonant controller in parallel with the disturbance observation channel of the improved linear extended state observer to construct a quasi-resonant improved linear extended observer; and designing a control law to construct a quasi-resonant improved linear active disturbance rejection controller based on the quasi-resonant improved linear extended state observer. This patent application fails to address the parameter coupling problem and has limited ability to suppress non-single-frequency periodic disturbances. Summary of the Invention

[0004] To overcome the problems existing in the prior art, the present invention aims to provide a linear active disturbance rejection control method and system for the speed loop of a permanent magnet synchronous motor. By decoupling parameters, the dynamic response speed and disturbance rejection capability can be controlled separately. By introducing a repetitive controller in the first-stage linear extended state observer, the ability of the linear active disturbance rejection controller to suppress high-frequency periodic disturbances is enhanced. By using a two-stage cascaded linear extended state observer structure, the ability of the linear active disturbance rejection controller to suppress higher-order disturbances is improved.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor, employing an improved linear active disturbance rejection controller; the improved linear active disturbance rejection controller uses a proportional-integral-derivative structure and a repetitive controller as a first-level linear extended state observer, and cascades a traditional linear extended state observer as a second-level observer; wherein, the construction method of the improved linear active disturbance rejection controller includes the following steps: Define the total system disturbance as an extended state variable; define the changes in the internal parameters of the permanent magnet synchronous motor, the load disturbance, the friction disturbance, and the unknown system disturbance as the total disturbance, set the total disturbance as an extended state variable, and obtain the extended state equation based on the speed loop; The difference between the given mechanical angular velocity and the estimated mechanical angular velocity by the decoupled repetitive control linear extended state observer is used to perform a proportional operation to obtain the control quantity; the difference between the control quantity and the estimated total disturbance by the decoupled repetitive control linear extended state observer is used to obtain the inputs of the decoupled repetitive control linear extended state observer and the traditional linear extended state observer. The first error is obtained by subtracting the actual mechanical angular velocity from the mechanical angular velocity estimated by the decoupled repetitive control linear extended state observer; the second error is obtained by performing proportional and integral operations on the first error and then summing them; the third error is obtained by performing a differential operation on the second error and then introducing RC; the system disturbance estimated by the decoupled repetitive control linear extended state observer is obtained by summing the system disturbance estimated by the decoupled repetitive control linear extended state observer with the input of the decoupled repetitive control linear extended state observer and then integrating it; the mechanical angular velocity estimated by the decoupled repetitive control linear extended state observer is obtained. The fourth error is obtained by subtracting the actual mechanical angular velocity from the mechanical angular velocity estimated by the traditional linear extended state observer. The fourth error is then integrated to obtain the system disturbance estimated by the traditional linear extended state observer. The fourth error, the system disturbance estimated by the decoupled repetitive control linear extended state observer, the system disturbance estimated by the traditional linear extended state observer, and the input of the traditional linear extended state observer are summed and then integrated to obtain the mechanical angular velocity estimated by the traditional linear extended state observer. The system disturbance estimated by the decoupled repetitive control linear extended state observer is summed with the system disturbance estimated by the traditional linear extended state observer to obtain the total disturbance estimated by the cascaded decoupled repetitive control linear extended state observer. The total disturbance estimated by the cascaded decoupled repetitive control linear extended state observer is introduced into the control law of the improved linear active disturbance rejection controller, generating the final control quantity that acts on the speed loop to control the speed of the permanent magnet synchronous motor.

[0006] Optionally, in a first-order linear extended state observer, the proportional-integral-differential structure is calculated by performing proportional-integral-differential calculations on the error feedback of a traditional linear extended state observer before the operation, and its expression is:

[0007] in, a The attenuation coefficient is... oh 01 The observer bandwidth in a first-order linear active disturbance rejection system is... oh c The controller bandwidth in linear active disturbance rejection. oh e z is the mechanical angular velocity, and z1 is the observer's mechanical angular velocity relative to the system. oh e The estimated value.

[0008] Optionally, the error transfer function expression of the first-order linear extended state observer after incorporating a proportional-integral-differential structure is:

[0009] in, a The attenuation coefficient is... oh 01 is the observer bandwidth in a first-order linear active disturbance rejection system; s is the Laplace operator.

[0010] Optionally, the transfer function of the repetitive controller added to the first-order linear extended state observer is:

[0011] in, k RC For the repetitive controller gain, k To compensate for the delay in the number of shots, N The system sampling frequency f s and input signal fundamental frequency f The ratio of 0, T s The system sampling period is Q ( s () is an auxiliary compensator. S (s) is a low-pass filter; s is the Laplace operator.

[0012] Optionally, the expression for the first-order linearly extended state observer is:

[0013] Where a is the attenuation coefficient, z1 is the observer's estimate of the system's mechanical angular velocity, z2 is the observer's estimate of the system's disturbance, and ω eWhere b is the mechanical angular velocity, and b0 is the input control gain; G RC This is the transfer function for the repetitive controller.

[0014] Optionally, the attenuation coefficient α is greater than 0.1 and less than 0.5.

[0015] Optionally, the expression for the second-order linearly extended state observer is:

[0016] in, s 1 represents the observer's estimate of the system's mechanical angular velocity. s 2 is the observer's view of the system, except z 2. Estimated values ​​of disturbances outside of 2.

[0017] Optionally, the formula for calculating the final control quantity is:

[0018] in, oh c The controller bandwidth in linear active disturbance rejection. oh e For mechanical angular velocity, z 1 represents the observer's estimate of the system's mechanical angular velocity. z 2 represents the observer's estimate of the system disturbance. b 0 represents the input control gain. s 2 is the observer's view of the system, except z 2. Estimated values ​​of disturbances outside of 2.

[0019] Secondly, the present invention provides a speed loop linear active disturbance rejection control system for a permanent magnet synchronous motor, which employs the aforementioned speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor.

[0020] Optionally, the speed loop linear active disturbance rejection control system of the permanent magnet synchronous motor includes: The speed loop LADRC regulator has an input terminal for inputting the given value and the actual value of the mechanical angular velocity, and an output terminal for outputting the q-axis reference current. A current-loop PI controller calculates the output signal using proportional and integral formulas to regulate the motor current, achieving precise control of the permanent magnet synchronous motor. Its input signals are the given speed and the feedback speed, and the final control output Iq is calculated accordingly. The Park inverse transformer unit has its input terminals used to input the q-axis voltage Uq and the d-axis voltage Ud, and its output terminals used to output the α-axis voltage and the β-axis voltage. The SVPWM module has its input terminals used to input α-axis and β-axis voltages, and its output terminals used to output three-phase voltages to the permanent magnet synchronous motor. The CLark converter unit has its input terminal used to input the three-phase current of the permanent magnet synchronous motor, and its output terminal used to output the α-axis current and β-axis current. The Park transformation unit has its input terminals used to input the α-axis current, β-axis current, and rotor angle, and its output terminals used to output the d-axis current and q-axis current.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention addresses the problems of coupling between disturbance estimation and dynamic performance in traditional linear active disturbance rejection systems, as well as the insufficient ability to estimate multi-source disturbances such as periodic and higher-order disturbances. It proposes a control method based on a decoupled cascaded linear extended state observer with a repetitive controller.

[0022] This invention incorporates a proportional-integral-derivative (PID) structure into a traditional linear active disturbance rejection system to decouple the parameters, achieving independent control between disturbance estimation and dynamic response speed. Then, a repetitive controller is added to a linear extended state observer to achieve estimation of periodic disturbances. Finally, a cascaded linear extended state observer is used to estimate higher-order disturbances through two-stage disturbance estimation and compensation.

[0023] Compared with traditional methods, this invention improves the system's ability to suppress periodic and high-order disturbances, and enhances the system's control accuracy. This invention achieves independent control of dynamic response speed and disturbance rejection capability through parameter decoupling; it enhances the linear active disturbance rejection controller's ability to suppress high-frequency periodic disturbances; and it improves the linear active disturbance rejection controller's ability to suppress high-order disturbances. Attached Figure Description

[0024] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a block diagram of an improved linearly extended state observer according to an embodiment of the present invention; Figure 2 This is a block diagram of a PMSM control system with an improved speed loop linear active disturbance rejection controller according to an embodiment of the present invention; Figure 3(a) is a traditional PI controller according to an embodiment of the present invention; (b) is a traditional LADRC (T-LADRC, Traditional Linear Active Disturbance Rejection Control); (c) is a common second-order cascaded LADRC (S-LADRC, Second-order Cascaded Linear Active Disturbance Rejection Control); and (d) is a comparison chart of speed fluctuations under sudden loads for an improved LADRC (C-DRC-LADRC, Cascaded-Decoupled Repetitive-Control Linear Active Disturbance Rejection Control) controller according to an embodiment of the present invention. Figure 4 The following is a comparison of the speed response curves of (a) a conventional PI controller according to an embodiment of the present invention, (b) a conventional LADRC, (c) a common two-stage cascaded LADRC, and (d) an improved LADRC controller according to an embodiment of the present invention under constant operation under periodic disturbances. Figure 5 The startup process curves of a traditional PI controller, a traditional LADRC, a common two-stage cascaded LADRC, and an improved LADRC controller according to embodiments of the present invention are compared under constant load conditions. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they 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 orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0028] When an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments. The use of the term "horizontal" does not imply that the component is required to be absolutely horizontal, but rather that it may be slightly tilted. "Horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0029] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] The present invention will now be described in detail with reference to the accompanying drawings.

[0032] Permanent magnet synchronous motors (PMSMs) are widely used in various fields such as defense, automotive, industry, and agriculture due to their advantages of simple structure, high power density, and high reliability. Traditional PI (Proportional-Integral) controllers rely on speed deviations for compensation. This lag inevitably leads to significant speed drops or rebounds in scenarios requiring high dynamic load disturbance resistance. Under extreme conditions, PI controllers can experience integral saturation, resulting in significant de-inflation and overshoot. Furthermore, many disturbances exist in the control system of a PMSM, and PI controllers cannot directly estimate external disturbances. Linear Active Disturbance Rejection Control (LADRC) can actively identify system disturbances and directly feedforward to cancel them in the control input. This results in speed drops for LADRCs being significantly lower than those for PI controllers, and it avoids integral saturation, leading to smoother speed transitions between different operating conditions.

[0033] Traditional linear active disturbance rejection controllers still have considerable room for improvement in parameter decoupling and enhancing their ability to suppress multi-source disturbances.

[0034] The present invention discloses a speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor, which employs an improved linear active disturbance rejection controller for control. The improved linear active disturbance rejection controller uses a proportional-integral-derivative structure and a repetitive controller as a first-level linear extended state observer, and cascades a traditional linear extended state observer as a second-level observer. The improved linear active disturbance rejection controller includes: a decoupled first-level linear state observer based on a repetitive controller and a cascaded improved LADRC.

[0035] Decoupled first-order linear state observers based on repetitive controllers include: 1) Proportional-Integral-Derivative Correction Component: The proportional-integral-derivative (PID) calculation is performed on the error feedback of the traditional (LESO, Linear Extended State Observer) system before the actual computation. The expression is:

[0036]

[0037] in, a The attenuation coefficient is... oh 01 The observer bandwidth in a first-order linear active disturbance rejection system is... oh c The controller bandwidth in linear active disturbance rejection. ohe z is the mechanical angular velocity, and z1 is the observer's mechanical angular velocity relative to the system. oh e The estimated value.

[0038] The newly added proportional-integral-differential term can transform the denominator structure of the error transfer function to contain only... oh A score of 0 oh 0 is used to adjust the observer's perturbation estimation capability. oh c Used to regulate the dynamic response speed of the system, the two are completely decoupled and the parameters can be tuned independently.

[0039] 2) Introduction of the repetitive controller: The repetitive controller is introduced into LESO, and its expression is:

[0040] in, k RC For the repetitive controller gain, k To compensate for the delay in the number of shots, N The system sampling frequency f s and input signal fundamental frequency f The ratio of 0, T s The system sampling period is Q ( s () is an auxiliary compensator. S (s) is a low-pass filter; s is the Laplace operator.

[0041] The newly added repetitive controller can exhibit high-gain resonant peaks at the fundamental frequency and its integer multiples, improving the linearly extended state observer's ability to estimate periodic disturbances and achieving effective suppression of periodic disturbances by the system. This can be achieved by adjusting the gain of the repetitive controller. k RC Auxiliary compensator Q (s) and delayed beats k It can achieve high-gain suppression of periodic disturbances at specific frequencies.

[0042] 3) Improved Level 1 LESO: The expression for decoupled LESO based on a repetitive controller is:

[0043]

[0044] in, z 1 represents the observer's estimate of the system's mechanical angular velocity. z 2 represents the observer's estimate of the system disturbance. oh e For mechanical angular velocity,b 0 represents the input control gain.

[0045] Improved LADRC cascade configurations include: 1) Second-level LESO: Further estimation of unknown disturbances Its expression is:

[0046] in, s 1 represents the observer's estimate of the system's mechanical angular velocity. s 2 is the observer's view of the system, except z 2. Estimated values ​​of disturbances outside of 2.

[0047] The final control quantity is generated through dual disturbance compensation:

[0048] in, oh c The controller bandwidth in linear active disturbance rejection. oh e For mechanical angular velocity, z 1 represents the observer's estimate of the system's mechanical angular velocity. z 2 represents the observer's estimate of the system disturbance. b 0 represents the input control gain. s 2 is the observer's view of the system, except z 2. Estimated values ​​of disturbances outside of 2.

[0049] 2) Improved LADRC: The LESO expression in the final improved LADRC design is:

[0050] Example 1 This embodiment of a speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor employs an improved linear active disturbance rejection controller. The improved linear active disturbance rejection controller uses a proportional-integral-derivative structure and a repetitive controller as a first-level linear extended state observer, and cascades a traditional linear extended state observer as a second-level observer.

[0051] The improved method for constructing a linear active disturbance rejection controller includes the following steps: The structure of the first-order linear control state observer is as follows: first, proportional-integral-derivative calculations are performed on the error feedback of the traditional LESO, and then observation is performed. The decoupled LESO expression is designed as follows:

[0052] The newly added proportional-integral-differential correction stage can transform the denominator structure of the error transfer function to contain only... ohPolynomials of 0 oh 0 is used to adjust the observer's perturbation estimation capability. oh c Used to regulate the dynamic response speed of the system, the two are completely decoupled and the parameters can be tuned independently.

[0053] The expression for introducing the repetitive controller into LESO is:

[0054] in, k RC For the repetitive controller gain, k To compensate for the delay in the number of shots, N The system sampling frequency f s and input signal fundamental frequency f The ratio of 0, T s The system sampling period is Q ( s () is an auxiliary compensator. S (s) is a low-pass filter.

[0055] The newly added repetitive controller can exhibit high-gain resonant peaks at the fundamental frequency and its integer multiples, improving the linear extended state observer's ability to estimate periodic disturbances and enabling the system to effectively suppress periodic disturbances.

[0056] The final expression for the decoupled LESO based on a repetitive controller is as follows:

[0057]

[0058] The designed expression for the second-order LESO is:

[0059] The final control quantity is generated through dual disturbance compensation:

[0060] The final designed decoupled cascaded LESO structure based on a repetitive controller is as follows: Figure 1 As shown, the expression for the designed observer is:

[0061] The designed improved LADRC achieves independent control of system disturbance estimation and dynamic response, and significantly improves the ability to suppress periodic disturbances and higher-order disturbances.

[0062] Example 2 Figure 1 This paper demonstrates a method for constructing a linearly extended state observer in a speed regulation system for a permanent magnet synchronous motor, including the following steps: Define the total system disturbance as an extended state variable; define the changes in the internal parameters of the permanent magnet synchronous motor, the load disturbance, the friction disturbance, and the unknown system disturbance as the total disturbance, set the total disturbance as an extended state variable, and obtain the extended state equation based on the speed loop; The given mechanical angular velocity is subtracted from the mechanical angular velocity estimated by DRC-LESO (Decoupled Repetitive-Control-Linear Extended State Observer), and the difference is proportionally calculated to obtain the control quantity. The control quantity is then subtracted from the total disturbance estimated by (C-DRC-LESO, Cascaded-Decoupled Repetitive-Control-Linear Extended State Observer) to obtain the inputs of DRC-LESO and T-LESO (Traditional Linear Extended State Observer). The first error is obtained by subtracting the actual mechanical angular velocity from the DRC-LESO estimated mechanical angular velocity; the second error is obtained by performing proportional and integral operations on the first error and then summing them; the third error is obtained by performing a differential operation on the second error and then introducing RC; the system disturbance estimated by DRC-LESO is obtained by summing the second error and the third error and performing an integral operation; the system disturbance estimated by DRC-LESO is obtained by summing it with the DRC-LESO input and then integrating it to obtain the mechanical angular velocity estimated by DRC-LESO. The fourth error is obtained by subtracting the actual mechanical angular velocity from the T-LESO estimated mechanical angular velocity; the fourth error is then integrated to obtain the T-LESO estimated system disturbance; the fourth error, the DRC-LESO estimated system disturbance, the T-LESO estimated system disturbance, and the T-LESO input are summed and then integrated to obtain the T-LESO estimated mechanical angular velocity; the DRC-LESO estimated system disturbance and the T-LESO estimated system disturbance are summed to obtain the C-DRC-LESO estimated total disturbance.

[0063] Example 3 This invention uses Simulink (a graphical simulation and model design environment in MATLAB) to verify the feasibility and superiority of the proposed improved speed loop LADRC in an uncontrolled permanent magnet synchronous motor. The simulation step size in the simulation experiment is 2×10⁻⁶. -6The control scheme uses vector control technology based on id=0. The permanent magnet synchronous motor control system based on a decoupled cascaded LESO speed loop controller with a repetitive controller proposed in this invention is as follows: Figure 2 As shown in Table 1, the motor parameters in the simulation experiment are as follows.

[0064] Figure 2 A speed loop linear active disturbance rejection control system for a permanent magnet synchronous motor is shown, including: The speed loop LADRC regulator has an input terminal for inputting the given value of the mechanical angular velocity and the actual value of the mechanical angular velocity, and an output terminal for outputting the q-axis reference current. A current-loop PI controller calculates the output signal using proportional and integral formulas to regulate the motor current, achieving precise control of the permanent magnet synchronous motor. Its input signals are the given speed and the feedback speed, and the final control output Iq is calculated accordingly. The Park inverse transformer unit has its input terminals used to input the q-axis voltage Uq and the d-axis voltage Ud, and its output terminals used to output the α-axis voltage and the β-axis voltage. The SVPWM module has its input terminals used to input α-axis and β-axis voltages, and its output terminals used to output three-phase voltages to the permanent magnet synchronous motor. The CLark converter unit has its input terminal used to input the three-phase current of the permanent magnet synchronous motor, and its output terminal used to output the α-axis current and β-axis current. The Park transformation unit has its input terminals used to input the α-axis current, β-axis current, and rotor angle, and its output terminals used to output the d-axis current and q-axis current.

[0065] Specifically, the output of the LADRC controller of the speed loop is connected to the input of the current loop PI regulator. The output of the current loop PI regulator is connected to the Park inverter unit. The output of the Park inverse converter unit is connected to the SVPWM unit. The output of the SVPWM unit is connected to the permanent magnet synchronous motor unit. The output of the permanent magnet synchronous motor unit is connected to the CLark converter unit and the speed loop PI regulator unit, respectively. The output of the CLark converter unit is connected to the Park unit. The output of the Park converter unit is connected to the current loop PI regulator unit. The output of the speed loop LADRC regulator unit is connected to the current loop PI regulator unit.

[0066] The speed loop LADRC regulator estimates the total system disturbance using LESO and applies this total disturbance to the speed loop to suppress the system disturbance. After disturbance suppression of the calculated control quantity, the setpoint for the q-axis current loop is obtained.

[0067] The current-loop PI controller obtains the output signal through proportional and integral calculations to adjust the motor speed, achieving precise control of the permanent magnet synchronous motor. In the current loop, the PI controller operates based on the Id=0 principle, adjusting the given Id=0 with the Iq obtained from LADRC, and then performing an inverse Park transform to finally obtain the output quantities Ud and Uq.

[0068] The Clarke transform unit is used to convert the sampled three-phase current signal into a Clarke transform. α-β Current components iα and iβ in a two-phase stationary coordinate system.

[0069] The Park transformation unit is used to further convert the two-phase current components iα and iβ into a synchronous rotating coordinate system via the Park transformation. dq Under-axis current components and .

[0070] The Park inverse converter unit is used to receive voltage signals. U d and voltage signal U q Output voltage signals respectively U α and U β .

[0071] The SVPWM module is used to receive voltage signals. U α and U β The result is then input into a three-phase inverter, which in turn converts the received signal from the PWM modulator into three-phase AC power for input into the permanent magnet synchronous motor.

[0072] The linear extended state observer estimates the extended state variables of the system based on the measured values ​​of the system's external variables, providing a practical possibility for the technical implementation of state feedback. The total system disturbance is obtained by processing the actual mechanical angular velocity and the LESO-estimated mechanical angular velocity.

[0073] The linear extended state observer (LESO) incorporates RC (Resonant Controlled Regulator) to suppress disturbances at the system's set frequency and its integer multiples. Furthermore, a cascaded structure and PID (PID Calculation) are used to decouple the disturbance estimation accuracy and the system's dynamic response speed, respectively, and to improve LESO's ability to estimate higher-order disturbances.

[0074] Table 1

[0075] The following simulation experiments compare the performance of the improved LADRC controller with that of the traditional PI controller, the traditional LADRC, and the ordinary two-stage cascaded LADRC.

[0076] Figure 3 The speed waveforms of a PI controller, a traditional LADRC, a standard two-stage cascaded LADRC, and an improved LADRC under a sudden constant load were compared. According to simulation waveforms, the PI controller experiences a speed drop of 51 rpm under a sudden load increase on top of a periodic disturbance, with a settling time of approximately 0.053 s. For the traditional LADRC and the standard two-stage cascaded LADRC, the speed drops are 80 rpm and 113 rpm, respectively, with settling times of 0.021 s. Compared to the PI controller, both the traditional LADRC and the standard two-stage cascaded LADRC reduce settling time by sacrificing speed drop. The decoupled cascaded LADRC based on a repetitive controller used in this invention ensures the shortest settling time while minimizing speed drop. This demonstrates the decoupling of the proportional-integral-derivative (PI-DE) correction stage from the controller parameters, avoiding the contradiction between disturbance estimation capability and system dynamic response. Furthermore, due to the introduction of the repetitive controller, the speed fluctuation is also minimal compared to other control methods, demonstrating the improved LADRC's better suppression capability against periodic disturbances.

[0077] Figure 4 The speed response of a PI controller, a traditional LADRC, a standard two-stage cascaded LADRC, and an improved LADRC under sudden periodic load was compared. According to simulation waveforms, the speed fluctuation of the PI controller under periodic disturbances was 19 rpm, while the speed fluctuations of the traditional LADRC and the standard two-stage cascaded LADRC were 17 rpm and 17 rpm respectively, indicating that the suppression capability of the traditional and cascaded LADRCs for periodic disturbances was not significantly improved. The decoupled cascaded LADRC based on repetitive control used in this invention reduced the speed fluctuation to 8 rpm under periodic load conditions, a 57.9% reduction compared to other controllers. This is attributed to the high gain suppression of periodic disturbances provided by the repetitive controller, which improves the LADRC's suppression capability for disturbances at specific frequencies, demonstrating its superiority in suppressing periodic disturbances.

[0078] Figure 5The start-up speed response of four controllers under a constant load of 5N was compared. Simulation waveforms show that PI control exhibits significant overshoot and a long settling time, while the traditional LADRC has an overshoot of approximately 2% and a settling time of 0.07s. Compared to the previous two controllers, the cascaded LESO provides more accurate initial disturbance estimation, reduces the overshoot to approximately 1.8%, and has a smoother response, but exhibits oscillation. The decoupled cascaded LADRC based on repetitive control achieves zero or minimal overshoot with the shortest rise time of 0.03s. This is mainly attributed to the improved controller bandwidth due to corrective decoupling. oh c With observer bandwidth oh Independent tuning avoids the observation lag during startup caused by coupling between the two components in traditional LADRC. At the same time, the repetitive controller and cascaded LESO can quickly estimate and compensate for periodic and higher-order disturbance components during startup, thus achieving a smooth, overshoot-free acceleration process.

[0079] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0080] Finally, 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 it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A method for linear active disturbance rejection control of the speed loop of a permanent magnet synchronous motor, characterized in that, An improved linear active disturbance rejection controller is used for control; the improved linear active disturbance rejection controller uses a proportional-integral-derivative structure and a repetitive controller as a first-level linear extended state observer, and a traditional linear extended state observer is cascaded as a second-level observer; the construction method of the improved linear active disturbance rejection controller includes the following steps: Define the total system disturbance as an extended state variable; define the changes in the internal parameters of the permanent magnet synchronous motor, the load disturbance, the friction disturbance, and the unknown system disturbance as the total disturbance, set the total disturbance as an extended state variable, and obtain the extended state equation based on the speed loop; The difference between the given mechanical angular velocity and the estimated mechanical angular velocity by the decoupled repetitive control linear extended state observer is used to perform a proportional operation to obtain the control quantity; the difference between the control quantity and the estimated total disturbance by the decoupled repetitive control linear extended state observer is used to obtain the inputs of the decoupled repetitive control linear extended state observer and the traditional linear extended state observer. The first error is obtained by subtracting the actual mechanical angular velocity from the mechanical angular velocity estimated by the decoupled repetitive control linear extended state observer; the second error is obtained by performing proportional and integral operations on the first error and then summing them; the third error is obtained by performing a differential operation on the second error and then introducing RC; the system disturbance estimated by the decoupled repetitive control linear extended state observer is obtained by summing the system disturbance estimated by the decoupled repetitive control linear extended state observer with the input of the decoupled repetitive control linear extended state observer and then integrating it; the mechanical angular velocity estimated by the decoupled repetitive control linear extended state observer is obtained. The fourth error is obtained by subtracting the actual mechanical angular velocity from the mechanical angular velocity estimated by the traditional linear extended state observer. The fourth error is then integrated to obtain the system disturbance estimated by the traditional linear extended state observer. The fourth error, the system disturbance estimated by the decoupled repetitive control linear extended state observer, the system disturbance estimated by the traditional linear extended state observer, and the input of the traditional linear extended state observer are summed and then integrated to obtain the mechanical angular velocity estimated by the traditional linear extended state observer. The system disturbance estimated by the decoupled repetitive control linear extended state observer is summed with the system disturbance estimated by the traditional linear extended state observer to obtain the total disturbance estimated by the cascaded decoupled repetitive control linear extended state observer. The total disturbance estimated by the cascaded decoupled repetitive control linear extended state observer is introduced into the control law of the improved linear active disturbance rejection controller, generating the final control quantity that acts on the speed loop to control the speed of the permanent magnet synchronous motor.

2. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, In a first-order linear extended state observer, the proportional-integral-differential structure is calculated by performing proportional-integral-differential operations on the error feedback of a traditional linear extended state observer before the operation is performed. Its expression is: in, a The attenuation coefficient is... ω 01 The observer bandwidth in a first-order linear active disturbance rejection system is... ω c The controller bandwidth in linear active disturbance rejection. ω e z is the mechanical angular velocity, and z1 is the observer's mechanical angular velocity relative to the system. ω e The estimated value.

3. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The error transfer function expression for a first-order linear extended state observer after incorporating a proportional-integral-differential structure is: in, a The attenuation coefficient is... ω 01 is the observer bandwidth in a first-order linear active disturbance rejection system; s is the Laplace operator.

4. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The transfer function of the repetitive controller added to the first-order linear extended state observer is: in, k RC For the repetitive controller gain, k To compensate for the delay in the number of shots, N The system sampling frequency f s and input signal fundamental frequency f The ratio of 0, T s The system sampling period is Q ( s () is an auxiliary compensator. S (s) is a low-pass filter; s is the Laplace operator.

5. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The expression for a first-order linearly extended state observer is: Where a is the attenuation coefficient, z1 is the observer's estimate of the system's mechanical angular velocity, z2 is the observer's estimate of the system's disturbance, and ω e Where b is the mechanical angular velocity, and b0 is the input control gain; G RC This is the transfer function for the repetitive controller.

6. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 5, characterized in that, The attenuation coefficient α is greater than 0.1 and less than 0.

5.

7. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The expression for the second-order linearly extended state observer is: in, s 1 represents the observer's estimate of the system's mechanical angular velocity. s 2 is the observer's view of the system except z 2. Estimated values ​​of disturbances outside of 2.

8. The speed loop linear active disturbance rejection control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The formula for calculating the final control quantity is: in, ω c The controller bandwidth in linear active disturbance rejection. ω e For mechanical angular velocity, z 1 represents the observer's estimate of the system's mechanical angular velocity. z 2 represents the observer's estimate of the system disturbance. b 0 represents the input control gain. s 2 is the observer's view of the system except z 2. Estimated values ​​of disturbances outside of 2.

9. A speed loop linear active disturbance rejection control system for a permanent magnet synchronous motor, characterized in that, The speed loop linear active disturbance rejection control method of a permanent magnet synchronous motor as described in any one of claims 1 to 8 is used for control.

10. A speed loop linear active disturbance rejection control system for a permanent magnet synchronous motor according to claim 9, characterized in that, The speed loop linear active disturbance rejection control system of the permanent magnet synchronous motor includes: The speed loop LADRC regulator has an input terminal for inputting the given value and the actual value of the mechanical angular velocity, and an output terminal for outputting the q-axis reference current. The current loop PI regulator obtains the output signal through proportional and integral calculations to regulate the motor current and achieve precise control of the permanent magnet synchronous motor; its input signals are the given speed and the feedback speed, and the final control output Iq is calculated. The Park inverse transformer unit has its input terminals used to input the q-axis voltage Uq and the d-axis voltage Ud, and its output terminals used to output the α-axis voltage and the β-axis voltage. The SVPWM module has its input terminals used to input α-axis and β-axis voltages, and its output terminals used to output three-phase voltages to the permanent magnet synchronous motor. The CLark converter unit has its input terminal used to input the three-phase current of the permanent magnet synchronous motor, and its output terminal used to output the α-axis current and β-axis current. The Park transformation unit has its input terminals used to input the α-axis current, β-axis current, and rotor angle, and its output terminals used to output the d-axis current and q-axis current.

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