Self-adaptive desaturation active-disturbance-rejection control method for LCL grid-connected converter

Abstract

The invention provides a self-adaptive desaturation active-disturbance-rejection control method for an LCL grid-connected converter. The method comprises the following steps: acquiring components of a first-order active-disturbance-rejection controller under a rotating coordinate system; according to the effect of the amplitude limiter in the first-order active-disturbance-rejection controller, designing a self-adaptive desaturator, and replacing the amplitude limiter with the self-adaptive desaturator to obtain a self-adaptive desaturating active-disturbance-rejection controller; calculating control parameters of the adaptive desaturator according to the structure of the adaptive desaturating active disturbance rejection controller; and removing disturbance in the distributed power generation system by using the self-adaptive desaturation active disturbance rejection controller after the control parameters are determined. According to the method, the original excellent anti-disturbance characteristic of the active-disturbance-rejection controller is kept, and meanwhile, compared with a traditional amplitude limiting link, the method has better amplitude limiting capacity and higher response speed. And meanwhile, the adverse effect of the amplitude limiting link on the response speed of the system when the distributed power generation system has large disturbance is effectively avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and in particular relates to an adaptive desaturation self-disturbance rejection control method for an LCL grid-connected converter. Background Art

[0002] LCL grid-connected converter is the interface device between the public power grid and the new energy power generation equipment. Its performance directly affects the safe and stable operation of the distributed power generation system. Therefore, how to effectively improve the output current quality and anti-interference performance of the grid-connected converter has become a research hotspot for scholars at home and abroad. The self-disturbance rejection controller estimates the sum of internal and external disturbances and compensates them in real time in a feedforward manner by introducing an extended state observer, which greatly improves the anti-interference performance of the system and has a strong harmonic suppression capability within the entire control bandwidth.

[0003] As a derivative of the PID controller, the ADRC inherits the advantage of the PID controller in terms of strong engineering practicality. Therefore, the use of control strategies based on ADRC is conducive to achieving the simultaneous improvement of the output current quality and anti-interference performance of the grid-connected converter in actual engineering. Compared with the nonlinear ADRC, the linear ADRC has a simple structure and fewer control parameters, and is more suitable for engineering applications. However, at the moment of grid connection or when the current set value changes significantly, the system will produce a large overshoot due to the unchanged gain of the linear ADRC, which may trigger the overcurrent protection mechanism of the converter, or even burn out the power switch device, causing irreversible damage to the grid-connected converter.

[0004] The existing technical solution is to add a limiting link after the output of the anti-disturbance controller. Due to output saturation, the system will not be able to return to the set value for a long period of time, which prolongs the adjustment time of the system and affects the response speed. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides an adaptive desaturation auto-disturbance rejection control method for an LCL grid-connected converter. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] An adaptive desaturation auto-disturbance rejection control method for an LCL grid-connected converter includes:

[0007] S100, obtaining components of a first-order active disturbance rejection controller in a rotating coordinate system, wherein the components include a linear state error feedback controller, a disturbance compensation processor, a linear extended state observer, and a limiter;

[0008] S200, designing an adaptive desaturator according to the function of the limiter in the first-order active disturbance rejection controller, and using the adaptive desaturator to replace the limiter to obtain an adaptive desaturation active disturbance rejection controller;

[0009] S300, calculating control parameters of the adaptive desaturator according to the structure of the adaptive desaturation anti-disturbance controller, the control parameters including a steady-state modulation wave amplitude, a threshold at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude, and an adaptive saturation coefficient;

[0010] S400, using the adaptive desaturation auto-disturbance rejection controller after the control parameters are determined to remove disturbances in the distributed generation system.

[0011] Beneficial effects:

[0012] The present invention provides an adaptive desaturation auto-disturbance rejection control method for an LCL grid-connected converter, obtaining the components of a first-order auto-disturbance rejection controller in a rotating coordinate system; designing an adaptive desaturator according to the role of the limiter in the first-order auto-disturbance rejection controller, and using it to replace the limiter to obtain an adaptive desaturation auto-disturbance rejection controller; calculating the control parameters of the adaptive desaturator according to the structure of the adaptive desaturation auto-disturbance rejection controller; using the adaptive desaturation auto-disturbance rejection controller after the control parameters are determined to remove disturbances in a distributed power generation system. The method of the present invention not only maintains the original excellent anti-disturbance characteristics of the auto-disturbance rejection controller, but also has better limiting capability and faster response speed than the traditional limiting link. At the same time, it effectively avoids the adverse effects of the limiting link on the system response speed when there is a large disturbance in the distributed power generation system.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a flow chart of an adaptive desaturation self-disturbance rejection control method for an LCL grid-connected converter provided by the present invention;

[0015] Figure 2 It is the block diagram of the traditional first-order ADRC in the rotating coordinate system;

[0016] Figure 3 is a schematic diagram of an adaptive desaturation auto-disturbance rejection controller provided by the present invention;

[0017] Figure 4 It is a structural schematic diagram of the LCL grid-connected converter provided by the present invention;

[0018] Figure 5 It is a schematic diagram of the converter output current waveform (without limiter) when a given current suddenly changes;

[0019] Figure 6 It is a schematic diagram of the output current waveform of the converter when a given current suddenly changes (with a limited traditional limiter);

[0020] Figure 7It is a schematic diagram of the converter output current waveform (with the adaptive desaturation anti-disturbance controller proposed by the present invention) when a given current suddenly changes. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0022] like Figure 1 As shown, the present invention provides an LCL grid-connected converter adaptive desaturation self-disturbance rejection control method comprising:

[0023] S100, obtaining components of a first-order active disturbance rejection controller in a rotating coordinate system, wherein the components include a linear state error feedback controller, a disturbance compensation processor, a linear extended state observer, and a limiter;

[0024] refer to Figure 2 , Figure 2 This is the block diagram of the traditional first-order ADRC in the rotating coordinate system. Figure 2 In the figure, the first-order ADRC is composed of ① linear state error feedback controller, ② disturbance compensation, ③ linear extended state observer and ④ limiting link. The input of the first-order ADRC is the current set value Igdq* of the d-axis or q-axis; the current set value Igdq* is subtracted from the output of the linear extended state observer and then input to the linear state error feedback controller; the linear state error feedback controller is subtracted from the output of the linear extended state observer and then input to the disturbance compensation processor; the disturbance compensation processor outputs the controller output voltage udq of the d-axis or q-axis to the input of the linear extended state observer and the input of the limiter; the output of the limiter is connected to the input of the AC converter and the LCL filter; the AC converter and the LCL filter also input the grid voltage ugdq, and output the output current igdq of the d-axis or q-axis to the input of the linear extended state observer, and the disturbance compensation coefficient of the disturbance compensation processor is The feedback coefficient of the linear state error feedback controller is kp.

[0025] S200, designing an adaptive desaturator according to the function of the limiter in the first-order active disturbance rejection controller, and using the adaptive desaturator to replace the limiter to obtain an adaptive desaturation active disturbance rejection controller;

[0026] exist Figure 2 Based on this, the adaptive desaturation auto-disturbance rejection controller proposed in this invention is as follows Figure 3 As shown. Figure 3In the embodiment, the input of the adaptive desaturation anti-disturbance controller is the current given value Igdq*; the current given value Igdq* is subtracted from the output of the linear extended state observer and then input to the linear state error feedback controller; the linear state error feedback controller is subtracted from the output of the linear extended state observer and then input to the disturbance compensation processor; the output controller of the disturbance compensation processor outputs the voltage udq to the input of the adaptive desaturator; the adaptive desaturator also inputs the steady-state modulation wave amplitude Uodq, and compares the threshold value uthdq of the actual modulation wave amplitude exceeding the steady-state modulation wave amplitude with the controller output voltage udq, and outputs the voltage utdq; the voltage utdq is added to the controller output voltage udq to obtain the voltage ubdq, and input to the linear extended state observer; the AC converter and the LCL filter also input the grid voltage ugdq, and output the grid-side current igdq to the input of the linear extended state observer; the linear extended state observer also inputs the controller output voltage udq, and outputs; the adaptive desaturation coefficient of the adaptive desaturator is ksdq.

[0027] As an optional implementation of the present invention, the adaptive desaturator further inputs a steady-state modulation wave amplitude Uodq, and compares the threshold value uthdq at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude with the controller output voltage udq, and the output voltage utdq includes:

[0028] The difference between udq and Uodq is recorded as uidq;

[0029] If |uidq|<uthdq, then multiply |uidq| by 0 and record it as utdq, and add utdq and udq as the input of the linear extended state observer. At this time, the input of the linear state observer is expressed as ubdq=utdq+udq=udq;

[0030] If |uidq|≥uthdq, then multiply |uidq| by ksdq and record it as utdq, and add utdq and udq as the input of the linear extended state observer. At this time, the input of the linear state observer is expressed as u bdq =u tdq +u dq =k sdq u dq -u odq |+u dq .

[0031] S300, calculating control parameters of the adaptive desaturator according to the structure of the adaptive desaturation anti-disturbance controller, the control parameters including a steady-state modulation wave amplitude, a threshold at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude, and an adaptive saturation coefficient;

[0032] S400, using an adaptive desaturation auto-disturbance rejection controller with determined parameters to remove disturbances in the distributed generation system.

[0033] The present invention provides an adaptive desaturation auto-disturbance rejection control method for an LCL grid-connected converter, obtaining the components of a first-order auto-disturbance rejection controller in a rotating coordinate system; designing an adaptive desaturator according to the role of the limiter in the first-order auto-disturbance rejection controller, and using it to replace the limiter to obtain an adaptive desaturation auto-disturbance rejection controller; calculating the control parameters of the adaptive desaturator according to the structure of the adaptive desaturation auto-disturbance rejection controller; using the adaptive desaturation auto-disturbance rejection controller after the control parameters are determined to remove disturbances in a distributed power generation system. The method of the present invention not only maintains the original excellent anti-disturbance characteristics of the auto-disturbance rejection controller, but also has better limiting capability and faster response speed than the traditional limiting link. At the same time, it effectively avoids the adverse effects of the limiting link on the system response speed when there is a large disturbance in the distributed power generation system.

[0034] As an optional implementation manner of the present invention, S300 includes:

[0035] S310, determining an electrical parameter expression of the LCL grid-connected converter, wherein the electrical parameter expression includes expressions of a three-phase inverter-side current, a grid-side current, a capacitor voltage, and a grid voltage;

[0036] refer to Figure 4 , the structural diagram of LCL grid-connected converter is as follows Figure 4 As shown, according to KCL and KVL, the electrical parameter expression can be obtained as follows:

[0037]

[0038] Wherein, iia(t), iib(t), iic(t) represent the side currents of items a, b, and c of the three-phase inverter at time t, respectively; iga(t), igb(t), igc(t) represent the grid-side currents of items a, b, and c of the three-phase inverter at time t, respectively; uca(t), ucb(t), and uc(t) represent the capacitor voltages of items a, b, and c of the three-phase inverter at time t, respectively; uga(t), ugb(t), and ugc(t) represent the grid voltages of items a, b, and c of the three-phase inverter at time t, respectively; uoa(t), uob(t), and uoc(t) represent the port voltages of items a, b, and c of the converter at time t, respectively, that is, the voltage between the output terminal of each phase and the midpoint of the AC side; L 1 , L 2 , C are the inverter side filter inductor, grid side filter inductor and filter capacitor respectively.

[0039] S320, converting the electrical parameter expression into a rotating coordinate system to obtain an electrical parameter expression in the rotating coordinate system;

[0040] By converting equation (1) to the rotating coordinate system, we can get the electrical parameter expression in the rotating coordinate system, which is expressed as:

[0041]

[0042] in,

[0043]

[0044] , iid(t) and iiq(t) represent the d-axis and q-axis variables of iix(t) in the rotating coordinate system, respectively, and x is a, b, and c respectively; igd(t) and igq(t) represent the d-axis and q-axis variables of igx(t) in the rotating coordinate system, respectively; ucd(t) and ucq(t) represent the d-axis and q-axis variables of ucx(t) in the rotating coordinate system, respectively; ugd(t) and ugq(t) represent the d-axis and q-axis variables of ugx(t) in the rotating coordinate system, respectively; uod(t) and uoq(t) represent the d-axis and q-axis variables of uox(t) in the rotating coordinate system, respectively; ω 0 is the fundamental frequency.

[0045] S330, setting the differential term in the electrical parameter expression in the rotating coordinate system to zero, and obtaining the expression of the steady-state modulation wave fundamental wave amplitude in the d-axis and q-axis;

[0046] Let the differential term in equation (2) be zero, then we can get the expression of the steady-state modulation wave fundamental amplitude under the d-axis and q-axis, which is expressed as:

[0047]

[0048] Wherein, Uod and Uoq are the steady-state fundamental amplitudes of uod(t) and uoq(t), respectively; Iid and Iiq are the steady-state fundamental amplitudes of iid(t) and iiq(t), respectively; Igd and Igq are the steady-state fundamental amplitudes of igd(t) and igq(t), respectively; Ugd and Ugq are the steady-state fundamental amplitudes of ugd(t) and ugq(t), respectively.

[0049] S340, according to the principle that when the distributed generation system enters a stable state, the fundamental amplitudes of the inverter-side current and the grid-side current are both given values, the expression of the steady-state modulation wave fundamental amplitude is converted to obtain the steady-state modulation wave fundamental amplitude;

[0050] Since the grid-connected converter uses the grid voltage as the phase-locking reference, it is considered that Ugq=0; at the same time, since the fundamental amplitudes of the inverter side current and the grid side current are the same, after the system enters the steady state, the fundamental amplitudes of the inverter side current and the grid side current are both given values. Therefore, Iid=Igd=Igd*, Iiq=Igq=Igq*, so the steady-state modulation wave fundamental amplitude is converted by equation (3), which is expressed as:

[0051]

[0052] S350, setting the threshold value of the actual modulation wave amplitude exceeding the steady-state modulation wave amplitude to km times the steady-state modulation wave fundamental wave amplitude;

[0053] The threshold value of the actual modulation wave amplitude exceeding the steady-state modulation wave amplitude includes: the threshold values ​​of the actual modulation wave amplitude of the d-axis and the q-axis exceeding the steady-state modulation wave amplitude, which are respectively expressed as:

[0054]

[0055] In the formula, km is a pre-set multiple value, which should not be too large and can be selected according to the system overshoot requirements.

[0056] S360, calculating an adaptive saturation coefficient according to the principle that the adaptive saturation coefficient changes with the amplitude of the steady-state modulation wave fundamental wave.

[0057] The desaturation coefficient ksdq changes with the magnitude of the steady-state modulation wave amplitude Uodq of the d-axis or q-axis. According to formula (4), the desaturation coefficient ksdq changes adaptively with the given value of the grid-side current Igdq* of the d-axis or q-axis. The adaptive saturation coefficient includes the adaptive saturation coefficients of the d-axis and the q-axis, which are respectively expressed as:

[0058]

[0059] Where ud and uq represent the components of the actual modulation wave amplitude on the d-axis and q-axis respectively.

[0060] So, combined Figure 3 It can be seen that the input ubdq of the linear extended state observer is

[0061]

[0062] This embodiment uses a two-level LCL grid-connected converter as the controlled object for Matlab / Simulink simulation verification. The system parameters are as follows: DC side voltage Udc = 700V, filter inductance L 1 =0.6mH, filter inductance L 2=0.3mH, filter capacitor C = 150uH, grid voltage ug = 182V, self-disturbance rejection controller parameters: kp = 6000, b 0 =400,β 1 =20000,β 2 =4×10 8 ; Adaptive desaturation link parameters: km=0.2. Figures 4 to 6 The figure shows the output current waveform of the converter in the dq rotating coordinate system and the abc stationary coordinate system when a given current suddenly changes (Igd* suddenly rises from 30A to 100A, and Igq* is always zero). Compared with the self-disturbance rejection control without the traditional limiting link and with the traditional limiting link, the self-disturbance rejection control with the adaptive desaturation link proposed by the present invention makes the system overshoot smaller and the adjustment speed faster. In summary, it is explained that the adaptive desaturation link proposed by the present invention for the self-disturbance rejection control not only does not affect the original characteristics of the self-disturbance rejection controller, but also has better limiting capability than the traditional limiting link, and the self-disturbance rejection control with the adaptive desaturation link has a faster response speed.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality of components or steps.

[0065] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An adaptive desaturation auto-disturbance rejection control method for an LCL grid-connected converter, characterized in that: include: S100, obtaining components of a first-order active disturbance rejection controller in a rotating coordinate system, wherein the components include a linear state error feedback controller, a disturbance compensation processor, a linear extended state observer, and a limiter; S200, designing an adaptive desaturator according to the function of the limiter in the first-order active disturbance rejection controller, and using the adaptive desaturator to replace the limiter to obtain an adaptive desaturation active disturbance rejection controller; S300, calculating control parameters of the adaptive desaturator according to the structure of the adaptive desaturation anti-disturbance controller, the control parameters including a steady-state modulation wave amplitude, a threshold at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude, and an adaptive saturation coefficient; S400, using the adaptive desaturation auto-disturbance rejection controller after the control parameters are determined to remove disturbances in the distributed generation system.

2. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 1, characterized in that: The input of the adaptive desaturation anti-disturbance controller is the current given value Igdq*; the current given value Igdq* is subtracted from the output of the linear extended state observer and then input to the linear state error feedback controller; the linear state error feedback controller is subtracted from the output of the linear extended state observer and then input to the disturbance compensation processor; the output controller of the disturbance compensation processor outputs the voltage udq to the input of the adaptive desaturator; the adaptive desaturator also inputs the steady-state modulation wave amplitude Uodq, and compares the threshold value uthdq at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude with the controller output voltage udq, and outputs the voltage utdq; the voltage utdq is added to the controller output voltage udq to obtain the voltage ubdq, and is input to the linear extended state observer; the AC converter and the LCL filter also input the grid voltage ugdq, and output the grid-side current igdq to the input of the linear extended state observer; the linear extended state observer also inputs the controller output voltage udq, and outputs it; the adaptive desaturation coefficient of the adaptive desaturator is ksdq.

3. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 2, characterized in that: The adaptive desaturator also inputs the d-axis or q-axis steady-state modulation wave amplitude Uodq, and compares the threshold value uthdq at which the actual modulation wave amplitude exceeds the steady-state modulation wave amplitude with the controller output voltage udq, and the output voltage utdq includes: The difference between udq and Uodq is recorded as uidq; If |uidq|<uthdq, then multiply |uidq| by 0 and record it as utdq, and add utdq and udq as the input of the linear extended state observer, expressed as ubdq=utdq+udq=udq; If |uidq|≥uthdq, then multiply |uidq| by ksdq and record it as utdq, and add utdq and udq as the input of the linear extended state observer, which is expressed as ubdq=utdq+udq=ksdq|udq-uodq|+udq.

4. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 1, characterized in that: S300 includes: S310, determining an electrical parameter expression of the LCL grid-connected converter, wherein the electrical parameter expression includes expressions of a three-phase inverter-side current, a grid-side current, a capacitor voltage, and a grid voltage; S320, converting the electrical parameter expression into a rotating coordinate system to obtain an electrical parameter expression in the rotating coordinate system; S330, setting the differential term in the electrical parameter expression in the rotating coordinate system to zero, and obtaining the expression of the steady-state modulation wave fundamental wave amplitude in the d-axis and q-axis; S340, according to the principle that when the distributed generation system enters a stable state, the fundamental amplitudes of the inverter-side current and the grid-side current are both given values, the expression of the steady-state modulation wave fundamental amplitude is converted to obtain the steady-state modulation wave fundamental amplitude; S350, setting the threshold value of the actual modulation wave amplitude exceeding the steady-state modulation wave amplitude to km times the steady-state modulation wave fundamental wave amplitude; S360, calculating an adaptive saturation coefficient according to the principle that the adaptive saturation coefficient changes with the amplitude of the steady-state modulation wave fundamental wave.

5. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 4, characterized in that: The electrical parameter expression in S310 is: Wherein, iia(t), iib(t), iic(t) represent the side currents of items a, b, c of the three-phase inverter at time t respectively; iga(t), igb(t), igc(t) represent the grid-side currents of items a, b, c of the three-phase inverter at time t respectively; uca(t), ucb(t), uc(t) represent the capacitor voltages of items a, b, c of the three-phase inverter at time t respectively; uga(t), ugb(t), ugc(t) represent the grid voltages of items a, b, c of the three-phase inverter at time t respectively; uoa(t), uob(t), uoc(t) represent the port voltages of items a, b, c of the converter at time t respectively; L1, L2, C represent the inverter side filter inductor, grid side filter inductor and filter capacitor respectively.

6. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 5, characterized in that: The electrical parameter expression in the rotating coordinate system in S320 is expressed as: in, iid(t) and iiq(t) respectively represent the d-axis and q-axis variables of iix(t) in the rotating coordinate system, and x is a, b, and c respectively; igd(t) and igq(t) respectively represent the d-axis and q-axis variables of igx(t) in the rotating coordinate system; ucd(t) and ucq(t) respectively represent the d-axis and q-axis variables of ucx(t) in the rotating coordinate system; ugd(t) and ugq(t) respectively represent the d-axis and q-axis variables of ugx(t) in the rotating coordinate system; uod(t) and uoq(t) respectively represent the d-axis and q-axis variables of uox(t) in the rotating coordinate system; ω0 is the fundamental frequency.

7. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 6, characterized in that: The expression of the steady-state modulation wave fundamental amplitude under the d-axis and q-axis in S330 is expressed as: Wherein, Uod and Uoq are the steady-state fundamental amplitudes of uod(t) and uoq(t), respectively; Iid and Iiq are the steady-state fundamental amplitudes of iid(t) and iiq(t), respectively; Igd and Igq are the steady-state fundamental amplitudes of igd(t) and igq(t), respectively; Ugd and Ugq are the steady-state fundamental amplitudes of ugd(t) and ugq(t), respectively.

8. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 7, characterized in that: The steady-state modulation wave fundamental amplitude in S340 includes: steady-state modulation wave fundamental amplitudes of the d-axis and the q-axis, which are respectively expressed as:

9. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 8, characterized in that: In S350, the thresholds of the actual modulation wave amplitude exceeding the steady-state modulation wave amplitude include: the thresholds of the actual modulation wave amplitudes of the d-axis and the q-axis exceeding the steady-state modulation wave amplitude, which are respectively expressed as: Where km is a preset multiple value.

10. The LCL grid-connected converter adaptive desaturation auto-disturbance rejection control method according to claim 9, characterized in that: The adaptive saturation coefficients in S360 include the adaptive saturation coefficients of the d-axis and the q-axis, which are respectively expressed as: Where ud and uq represent the components of the actual modulation wave amplitude on the d-axis and q-axis respectively.

Images