Damping remodeling and multi-frequency coupling effect suppression method for grid-connected converter based on active disturbance rejection control

Abstract

The present invention discloses a method and system for damping remodeling and multi-frequency coupling effect suppression of a grid-connected converter based on auto-disturbance rejection control, which relates to the field of broadband oscillation suppression of a new energy station grid-connected system, and includes the steps of: embedding a first-order linear auto-disturbance rejection control link into a phase-locked loop based on a dual generalized second-order integrator, and correcting the amplitude and phase characteristics of the admittance element characterizing the multi-frequency coupling effect in the three-phase grid-connected converter; and combining the corrected phase-locked loop correction transfer function with the current inner loop equation, voltage outer loop equation, sampling delay link equation, and main circuit equation based on the dual generalized second-order integrator to obtain a three-phase grid-connected converter system after damping remodeling. The method of the present invention suppresses the multi-frequency coupling component and the oscillation component, and simultaneously corrects the damping characteristics of the converter and the equivalent power grid under the influence of the multi-frequency coupling effect, thereby realizing the remodeling of the overall damping characteristics of the system and improving the robustness of the converter grid-connected system.

Description

Technical Field

[0001] The present invention relates to the field of broadband oscillation suppression of a new energy station grid-connected system, and in particular to a method and system for suppressing damping and multi-frequency coupling effects of a grid-connected converter based on auto-disturbance rejection control. Background Art

[0002] Under the current situation of large-scale access to the power grid of new energy power generation and its supporting power electronic grid-connected converters, the dynamic behavior of the system has become very complex, and unstable oscillation behavior has occurred frequently. Suppressing the multi-frequency coupling effect under the access of diversified power electronic equipment and solving the problem of system unstable oscillation are key tasks to achieve high-level new energy consumption.

[0003] Existing research mainly aims to modify the damping characteristics of the converter or grid side in the system from two aspects: adding hardware circuits / equipment and improving the system control mode to achieve oscillation suppression. Regarding the oscillation suppression idea of ​​adding hardware circuits / equipment, some studies have proposed to connect passive components such as resistors, inductors, capacitors, etc. in series and parallel in the grid-connected lines to directly modify the system damping, and some have connected additional converters in series, that is, active damping, to modify the system damping. These suppression methods are direct and effective, but they will significantly increase the system operating cost, increase losses, and reduce power generation efficiency. With the diversification of converter control strategies and operating modes, the frequency coupling effect cannot be ignored. Considering the complex frequency coupling effect and the phenomenon of oscillation instability caused by it, the design of the suppression strategy will be more complicated. Some studies have proposed a vehicle-grid low-frequency oscillation suppression method based on adaptive self-disturbance rejection. This method can achieve adaptive oscillation suppression, but does not consider the multi-frequency coupling effect, and the frequency band of concern is only in the low frequency band. It can be seen that the research on traditional oscillation suppression methods is mature, and most of the research on considering the mirror frequency coupling effect is achieved from the decoupling idea. However, this design idea is no longer applicable to the oscillation instability phenomenon under complex multi-frequency coupling effects. Therefore, it is urgent to propose an effective suppression strategy for the oscillation instability phenomenon of the converter grid-connected system considering the multi-frequency coupling effect from the perspective of impedance / admittance analysis. Summary of the invention

[0004] The main purpose of the present invention is to provide a method and system for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on self-disturbance rejection control, aiming to solve the technical problem in the prior art that broadband oscillations of a converter grid-connected system under the influence of multi-frequency coupling effects are difficult to suppress.

[0005] A method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control, comprising the steps of:

[0006] S10, embed the first-order linear anti-disturbance control link into a phase-locked loop based on a dual generalized second-order integrator, and perform amplitude and phase characteristic correction on the admittance element representing the multi-frequency coupling effect in the three-phase grid-connected converter, specifically including:

[0007] The first-order linear active disturbance rejection control link is embedded in a phase-locked loop based on a double generalized second-order integrator, wherein the first-order linear active disturbance rejection control link includes a linear extended state observer part, a linear error feedback part and a total disturbance part to be compensated;

[0008] A linear extended state observer part is constructed based on the Luenberger observer. The linear extended state observer part is used to reconstruct the controlled phase-locked loop and predict the total disturbance. The predicted total disturbance includes a first predicted disturbance and a second predicted disturbance. The linear error feedback part is used to perform linear processing on the first predicted disturbance and output linear feedback data. The total disturbance to be compensated part is used to perform compensation processing on the linear feedback data and the second predicted disturbance and output the predicted angular velocity. The difference between the predicted angular velocity and the ideal angular velocity is the angular velocity disturbance. , the total disturbance part to be compensated is compensated to eliminate the disturbance and suppress the multi-frequency coupling component and the oscillation component.

[0009] Considering the multi-frequency coupling effect, the first-order linear anti-disturbance control link is introduced to correct the phase-locked loop transfer function expression:

[0010]

[0011] in, is the angular velocity disturbance,

[0012] is a diagonal matrix of 1, The PCC point voltage considering the second-order small signal term is: for The frequency shift diagonal matrix of is the q-axis component of the voltage at the PCC point, and They are and The Toeplitz matrix, is the error angle of the phase-locked loop, The phase angle of the phase-locked loop output ， 、 is the voltage disturbance component in the dq rotating coordinate system after considering the amplitude and phase angle dynamics;

[0013] in, , is the controller bandwidth in the linear error feedback part, is the bandwidth of the LESO observer in the linear extended state observer part, is the Lablas operator, is the compensation disturbance parameter in the total disturbance part to be compensated,

[0014] S20, the corrected phase-locked loop correction transfer function is combined with the current inner loop equation, voltage outer loop equation, sampling delay link equation and main circuit equation based on the double generalized second-order integrator to obtain the three-phase grid-connected converter system after damping reshaping.

[0015] Furthermore, the function model of the tuning bandwidth of the linear extended state observer is: ,in, is the tuning bandwidth of the linear extended state observer part, , , is the bandwidth of the linearly extended state observer part.

[0016] Furthermore, based on the influence of voltage small disturbance signal and multi-frequency coupling effect on the converter main circuit, the converter main circuit small signal equation is established; specifically,

[0017] According to the main circuit topology of the converter, the expressions of the internal potential, output terminal voltage and output current of the converter are obtained;

[0018] The output voltage, output current, modulation signal under the combined converter control circuit and the expressions of output voltage, current and modulation signal under the dynamic influence of the phase-locked loop are used to derive the converter amplitude and phase admittance model. .

[0019] The present invention also provides an amplitude-phase impedance modeling system for multi-frequency coupling effects of a three-phase grid-connected converter system, comprising a processing device for implementing the steps of the above-mentioned method for damping reshaping and multi-frequency coupling effect suppression of the grid-connected converter based on self-disturbance rejection control.

[0020] Compared with the prior art, the method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control provided by the present invention has the following beneficial effects:

[0021] The present invention provides a method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control. The implementation process includes embedding a first-order linear active disturbance rejection control link into a phase-locked loop based on a dual generalized second-order integrator, correcting the amplitude and phase characteristics of the admittance element representing the multi-frequency coupling effect in the three-phase grid-connected converter system, and then analyzing and comparing the system frequency coupling component, damping characteristics and grid-connected voltage waveform under the condition of strong grid voltage imbalance before and after the damping reshaping of the converter system. The simulation results verify the effectiveness of the proposed damping reshaping and suppression method. At the same time, considering that the original phase-locked loop part of the grid-connected converter based on the dual second-order generalized integrator adopts proportional integral control, and its model order is 1st order, a first-order linear active disturbance rejection control loop (Liner Active Disturbance Rejection Controller, The LADRC) is used to replace the proportional-integral link to meet the control requirements; the introduction of the first-order linear anti-disturbance control link can efficiently reconstruct the total disturbance (predicted total disturbance) of the phase-locked loop link that causes the multi-frequency coupling effect, and the use of the control law (corrected phase-locked loop correction transfer function) can eliminate the total disturbance, suppress the multi-frequency coupling component and the oscillation component, and at the same time correct the damping characteristics of the converter and the equivalent power grid affected by the multi-frequency coupling effect, thereby realizing the reshaping of the overall damping characteristics of the system and improving the robustness of the converter grid-connected system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 It is a flow chart of the method for damping reshaping and multi-frequency coupling effect suppression of the grid-connected converter based on active disturbance rejection control in the present invention;

[0024] Figure 2 A control block diagram of a dual generalized second-order integrator phase-locked loop that introduces a first-order auto-disturbance rejection control link according to an embodiment of the present invention;

[0025] Figure 3 The Bode diagrams of the three-phase grid-connected converter side before and after the damping correction are compared in one embodiment of the present invention, wherein 3a is the amplitude characteristic curve diagram before and after the correction, and 3b is the phase characteristic curve diagram before and after the correction;

[0026] Figure 4 Bode diagrams comparing the damping before and after correction of the equivalent grid side of the three-phase grid-connected converter according to an embodiment of the present invention, wherein 4a is an amplitude characteristic curve diagram before and after correction, and 4b is a phase characteristic curve diagram before and after correction;

[0027] Figure 5 Bode diagrams comparing the total damping of the converter and the equivalent power grid before and after correction according to an embodiment of the present invention, wherein 5a is an amplitude characteristic curve diagram before and after correction, and 5b is a phase characteristic curve diagram before and after correction;

[0028] Figure 6 6a is the waveform diagram of the grid-connected current before and after correction of the converter system according to an embodiment of the present invention, wherein 6a is the waveform diagram of the grid-connected current before correction, and 6b is the waveform diagram of the grid-connected current after correction. DETAILED DESCRIPTION

[0029] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] Please refer to Figure 2 The control block diagram of the dual generalized second-order integrator phase-locked loop with the introduction of the first-order anti-disturbance control link is shown in Figure 1. After Clark transformation, the voltage component in the stationary coordinate system is obtained , , and then the voltage component is obtained after filtering by the DSOGI-QSG module , , and as the input of the phase-locked loop, the voltage component in the dq coordinate system is obtained through park transformation , , the phase-locked loop output phase angle is , The phase-locked loop outputs the actual angular velocity, is the ideal angular velocity, and the total disturbance compensation link is used to eliminate the actual angular velocity With ideal angular velocity Angular velocity disturbance between .

[0034] Please refer to Figure 1 , Figure 2 as well as Figure 3 , the present invention provides a method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control, comprising the steps;

[0035] S10, embed the first-order linear anti-disturbance control link into a phase-locked loop based on a dual generalized second-order integrator, and perform amplitude and phase characteristic correction on the admittance element representing the multi-frequency coupling effect in the three-phase grid-connected converter, specifically including:

[0036] The first-order linear active disturbance rejection control link is embedded in a phase-locked loop based on a double generalized second-order integrator, wherein the first-order linear active disturbance rejection control link includes a linear extended state observer part, a linear error feedback part and a total disturbance part to be compensated;

[0037] A linear extended state observer part is constructed according to the Luenberger observer. The linear extended state observer part is used to reconstruct the controlled phase-locked loop and predict the total disturbance. The predicted total disturbance includes a first predicted disturbance and a second predicted disturbance. The linear error feedback part is used to perform linear processing on the first predicted disturbance and output linear feedback data. The total disturbance to be compensated part is used to perform compensation processing on the linear feedback data and the second predicted disturbance and output a predicted angular velocity. The difference between the predicted angular velocity and the ideal angular velocity is the angular velocity disturbance. , the total disturbance part to be compensated is compensated to eliminate the disturbance and suppress the multi-frequency coupling component and the oscillation component.

[0038] Considering the multi-frequency coupling effect, the first-order linear anti-disturbance control link is introduced to correct the phase-locked loop correction transfer (angular velocity disturbance) function expression:

[0039]

[0040] in, is the angular velocity disturbance,

[0041] is a diagonal matrix of 1, The PCC point voltage considering the second-order small signal term is: for The frequency shift diagonal matrix of is the q-axis component of the voltage at the PCC point, and They are and The Toeplitz matrix, is the error angle of the phase-locked loop (i.e., the difference between the actual angle output by the phase-locked loop and the ideal angle), The phase angle of the phase-locked loop output ， 、 is the voltage disturbance component in the dq rotating coordinate system after considering the amplitude and phase angle dynamics;

[0042] in, , is the controller bandwidth in the linear error feedback part, is the bandwidth of the LESO observer in the linear extended state observer part, is the Lablas operator, is the compensation disturbance parameter in the total disturbance part to be compensated,

[0043] S20, the corrected phase-locked loop correction transfer function is combined with the current inner loop equation, voltage outer loop equation, sampling delay link equation and main circuit equation based on the double generalized second-order integrator to obtain the three-phase grid-connected converter system after damping reshaping.

[0044] The present invention provides a method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control. The implementation process includes embedding a first-order linear active disturbance rejection control link into a phase-locked loop based on a dual generalized second-order integrator, correcting the amplitude and phase characteristics of the admittance element representing the multi-frequency coupling effect in the three-phase grid-connected converter system, and then analyzing and comparing the system frequency coupling component, damping characteristics and grid-connected voltage waveform under the condition of strong grid voltage imbalance before and after the damping reshaping of the converter system. The simulation results verify the effectiveness of the proposed damping reshaping and suppression method. At the same time, considering that the original phase-locked loop part of the grid-connected converter based on the dual second-order generalized integrator adopts proportional integral control, and its model order is 1st order, a first-order linear active disturbance rejection control loop (Liner Active Disturbance Rejection Controller, The LADRC) is used to replace the proportional-integral link to meet the control requirements; the introduction of the first-order linear anti-disturbance control link can efficiently reconstruct the total disturbance (predicted total disturbance) of the phase-locked loop link that causes the multi-frequency coupling effect, and the use of the control law (corrected phase-locked loop correction transfer function) can eliminate the total disturbance, suppress the multi-frequency coupling component and the oscillation component, and at the same time correct the damping characteristics of the converter and the equivalent power grid affected by the multi-frequency coupling effect, thereby realizing the reshaping of the overall damping characteristics of the system and improving the robustness of the converter grid-connected system.

[0045] The method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control of the present invention comprises:

[0046] Step 1: When embedding the active disturbance rejection control link into the phase-locked loop based on dual generalized second-order integrators, the active disturbance rejection control loop is designed and parameters are selected. Considering that the original phase-locked loop based on dual second-order generalized integrators of the grid-connected converter adopts proportional-integral control and its model order is 1st order, a first-order linear active disturbance rejection control loop (Liner Active Disturbance Rejection Controller, LADRC) is selected to replace the proportional-integral link to meet the control requirements.

[0047] Step 2: The first-order linear anti-disturbance control link consists of a linear extended state observer part, a linear error feedback part, and a total disturbance to be compensated part. The linear extended state observer part is used to reconstruct the controlled object (reconstruct the controlled phase-locked loop) and observe the total disturbance (predict the total disturbance). Its output is the first predicted disturbance and the second predicted disturbance p ,make , , When , the first-order differential equation of the controlled phase-locked loop after being corrected by the first-order linear anti-disturbance control link is:

[0048]

[0049] in, , , , , , is the compensation disturbance parameter in the total disturbance part to be compensated, and its expanded form is:

[0050]

[0051] in, is the linear expansion parameter in the linear expansion state observer part.

[0052] Step 3: Construct the linear extended state observer part based on the Luenberger observer and obtain the following form:

[0053]

[0054] in is the estimated value of the state of x, is the state estimate of y; at this time, the gain matrix of the linear extended state observer is , the system matrix is , the input matrix is , so the linear extended state observer part can be expressed as:

[0055]

[0056] The characteristic polynomial of the linear extended state observer partial system (function model of the tuning bandwidth) is obtained as follows:

[0057]

[0058] Based on the partial bandwidth tuning method of the linear extended state observer, the characteristic roots are obtained as follows: , ,in is the LESO observer bandwidth.

[0059] Step 4: In the above bandwidth (bandwidth ) has the following relationship: , the first-order differential equation of the phase-locked loop after the introduction of the first-order linear anti-disturbance link should be corrected to:

[0060]

[0061] in, u 0 It is controlled by the linear error feedback part. u 0The linear error feedback part performs linear processing on the first predicted disturbance and outputs the linear feedback data, , r is the model setting value of the controlled phase-locked loop, and the Laplace transform is performed to obtain the expected closed-loop transfer function expression of the controlled object system at this time:

[0062]

[0063] in, and are the Pull-type transformation forms of y and r respectively, is the controller bandwidth in the linear error feedback section.

[0064] Step 5: Then derive the transfer function model of the phase-locked loop after introducing the first-order linear anti-disturbance control link:

[0065]

[0066] To characterize the multi-frequency coupling effect, Mapping to the multi-phase domain coordinate system After the introduction of the anti-disturbance control, the phase-locked loop link is a linear time-invariant transfer function, so Is The frequency shift diagonal matrix composed of and It also needs to be mapped to the multi-complex phase domain coordinate system. Therefore, the transfer function expression of the phase-locked loop after considering the multi-frequency coupling effect and introducing the self-disturbance rejection control correction is obtained:

[0067]

[0068] in for The frequency shift diagonal matrix of The PCC point voltage considering the second-order small signal term is: and respectively and The Toeplitz matrix, is the voltage disturbance component in the dq rotating coordinate system after considering the amplitude and phase angle dynamics, A diagonal matrix of 1. It is the corrected model of the phase-locked loop transfer function model in the multi-complex phase domain coordinate system.

[0069] Step 6: Combine the corrected PLL transfer function with the current inner loop equation, voltage outer loop equation, sampling delay link equation and main circuit equation based on double generalized second-order integrator to obtain the three-phase grid-connected converter system after damping reshaping. is the converter impedance model, It is the equivalent impedance model of the power grid.

[0070] Figure 2 The damping components corresponding to the 1st, 2nd and 3rd order frequency coupling effects of the converter are given. , ,and From the Bode diagrams before and after correction, it can be seen that after applying the method proposed in the present invention, the impedance amplitude characterizing the frequency coupling effect in the converter increases, and the higher the coupling frequency, the more obvious the increase in amplitude.

[0071] Figure 3 The damping components corresponding to the first-order, second-order, and third-order frequency coupling effects on the equivalent power grid side are given as follows: , and From the Bode plots before and after the correction, we can see that after the introduction of LADRC, the amplitudes of the impedance elements representing the frequency coupling effect are significantly reduced.

[0072] In order to further confirm the correction effect of the method proposed in the present invention on the complex amplitude phase admittance of the converter and the power grid, and the suppression effect on the multi-frequency coupling effect and oscillation, Figure 4 The complex circuit impedance model of the converter and the power grid before and after correction is given, namely: and From the Bode plot, we can see that the impedance amplitude of the converter complex phase domain increases slightly, while the impedance amplitude of the equivalent grid complex phase domain decreases significantly, especially in the low and medium frequency bands where the phase-locked loop and the voltage outer loop mainly work. Figure 3 , 4 , Figure 5 It can be seen that the application of the present invention in the converter grid-connected system under unbalanced conditions is achieved by correcting the complex amplitude phase impedance element that characterizes the frequency coupling effect, especially the impedance element on the equivalent grid side. On the other hand, it also illustrates that the present invention suppresses the derivative process of the multi-frequency coupling effect caused by the background harmonics of the grid, thereby achieving the suppression of system oscillation.

[0073] Figure 6 The grid-connected current waveforms of the converter before and after the introduction of the first-order linear anti-disturbance control correction are given. It can be seen that the system oscillation phenomenon has been effectively suppressed at this time, proving the effectiveness of the proposed method in the three-phase grid-connected converter system under unbalanced working conditions.

[0074] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control, characterized in that: Includes steps: S10, embed the first-order linear anti-disturbance control link into a phase-locked loop based on a dual generalized second-order integrator, and perform amplitude and phase characteristic correction on the admittance element representing the multi-frequency coupling effect in the three-phase grid-connected converter, specifically including: The first-order linear active disturbance rejection control link is embedded into a phase-locked loop based on a double generalized second-order integrator, wherein the first-order linear active disturbance rejection control link includes a linear extended state observer part, a linear error feedback part and a total disturbance part to be compensated; A linear extended state observer part is constructed according to the Luenberger observer. The linear extended state observer part is used to reconstruct the controlled phase-locked loop and predict the total disturbance. The predicted total disturbance includes a first predicted disturbance and a second predicted disturbance. The linear error feedback part is used to perform linear processing on the first predicted disturbance and output linear feedback data. The total disturbance to be compensated part is used to perform compensation processing on the linear feedback data and the second predicted disturbance and output a predicted angular velocity. The difference between the predicted angular velocity and the ideal angular velocity is the angular velocity disturbance. , the total disturbance part to be compensated is compensated to eliminate the disturbance and suppress the multi-frequency coupling component and the oscillation component. Considering the multi-frequency coupling effect, the first-order linear anti-disturbance control link is introduced to correct the phase-locked loop transfer function expression: in, is the angular velocity disturbance, is represented as a diagonal matrix of 1, The PCC point voltage considering the second-order small signal term is: Is The frequency shift diagonal matrix composed of for The frequency shift diagonal matrix, and They are and The Toeplitz matrix, is the error angle of the phase-locked loop ， 、 is the voltage disturbance component in the dq rotating coordinate system after considering the amplitude and phase angle dynamics; in, , is the phase angle of the phase-locked loop output, is the q-axis component of the voltage at the PCC point, is the controller bandwidth in the linear error feedback part, is the bandwidth of the LESO observer in the linear extended state observer part, is the Lablas operator, is the compensation disturbance parameter in the total disturbance part to be compensated, S20, the corrected phase-locked loop correction transfer function is combined with the current inner loop equation, voltage outer loop equation, sampling delay link equation and main circuit equation based on the double generalized second-order integrator to obtain the three-phase grid-connected converter system after damping reshaping.

2. The method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control according to claim 1, characterized in that: The function model of the tuning bandwidth of the linear extended state observer is: ,in, is the tuning bandwidth of the linear extended state observer part, , , is the bandwidth of the linearly extended state observer part.

3. A grid-connected converter damping reshaping and multi-frequency coupling effect suppression system based on active disturbance rejection control, characterized in that: It comprises a processing device, which is used to implement the steps of the method for damping reshaping and multi-frequency coupling effect suppression of a grid-connected converter based on active disturbance rejection control as described in any one of claims 1 or 2.

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