AH-VOC inverter high-gain robust voltage control method considering reactive power limitation

Abstract

The invention discloses an AH-VOC inverter high-gain robust voltage control method considering reactive power limitation, and the method comprises the steps: obtaining an inverter output voltage instruction under a two-phase static coordinate system in the operation process of an AH-VOC inverter; obtaining an inverter output voltage amplitude based on the inverter output voltage instruction; inputting the output voltage amplitude of the inverter into a configured high-gain robust voltage controller, and outputting a control rate; obtaining a reactive power compensation instruction based on the control rate; generating a current instruction under a two-phase static coordinate system based on the reactive power compensation instruction; and adjusting an inverter output voltage instruction based on the current instruction under the two-phase static coordinate system in combination with the inverter output current. According to the method, the nonlinear relation between the voltage amplitude and the output reactive power of the AH-VOC inverter is considered, and the limitation of the output reactive power of the inverter is fully considered, so that the voltage control response speed and precision are improved, and the system stability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage control, more particularly to a high-gain robust voltage control method for AH-VOC inverters considering reactive power limits. BACKGROUND

[0002] Grid Forming (GFM) inverters can achieve voltage synchronization by adjusting their output power, actively support the voltage and frequency of the system, and exhibit voltage source characteristics. The control strategies mainly include droop control, virtual synchronous machine control, and virtual oscillator control. AH-VOC inverters based on virtual oscillator control have small output voltage harmonics, adjustable power, and are more suitable for three-phase power systems. However, when the load is disturbed, there is a large steady-state deviation between the output voltage of the AH-VOC inverter and the rated value.

[0003] To address the voltage fluctuation problem of AH-VOC inverters during load switching, a large number of studies have proposed voltage control strategies from the aspects of optimizing control parameters and improving control structures. For example:

[0004] (1) Quedan A, Wang W, Ramasubramanian D, et al. An Adaptive Virtual Oscillator Control Structure for Grid-Forming Inverters [J]. IEEE Systems Journal, 2023, 17(3): 3447-3455. An optimization algorithm for AH oscillator parameters is proposed, which detects the relationship between the inverter terminal voltage and the preset value through a fixed time period, and adjusts the AH0 parameters adaptively to achieve voltage control of the inverter;

[0005] (2) Gurugubelli V, Ghosh A, Panda A K. Design and Implementation of Optimized Andronov-Hopf Oscillator Control Method for Parallel Inverters in Standalone Microgrid [J]. IEEE Transactions on Industry Applications, 2023, 59(6): 7013-7026. Considering the large range of AH-VOC control parameters, an improved sine-cosine algorithm (mSCA) based parameter optimization method is further proposed, which can achieve voltage regulation while optimizing the dynamic characteristics of the inverter.

[0006] (3) Document Luo S, Chen W, Li X, et al. A New Virtual Inertial Strategy for Andronov-Hopf Oscillator based Grid-forming Inverters [J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2024: 1-1. introduces a virtual inertia module based on a proportional-resonant controller, which can improve the dynamic characteristics of the AH-VOC inverter under grid frequency and load power fluctuations by changing the input of the AH oscillator.

[0007] The above strategies can achieve voltage regulation of the AH-VOC inverter to some extent, but on the one hand, they do not fully consider the nonlinear characteristics of the system, and there are problems of slow response speed and low regulation accuracy. On the other hand, there is a lack of stability analysis of the system after introducing the voltage control strategy.

[0008] Therefore, in the voltage control process, how to consider the nonlinear relationship between the amplitude of the AH-VOC inverter voltage and the output reactive power, and fully consider the limitation of the inverter output reactive power, so as to improve the response speed and accuracy of voltage control and improve the stability of the system, is a problem that the person skilled in the art needs to solve. SUMMARY

[0009] In view of the above problems, the present application provides an AH-VOC inverter high-gain robust voltage control method considering reactive power limitation to at least solve part of the technical problems mentioned in the background art.

[0010] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0011] The present application provides an AH-VOC inverter high-gain robust voltage control method considering reactive power limitation, comprising the following steps:

[0012] S1, during the operation of the AH-VOC inverter, obtaining the inverter output voltage command in the two-phase stationary coordinate system;

[0013] S2, obtaining the inverter output voltage amplitude based on the inverter output voltage command;

[0014] S3, inputting the inverter output voltage amplitude into the configured high-gain robust voltage controller to output the control rate;

[0015] S4, obtaining the reactive power compensation command based on the control rate;

[0016] S5, generating a current instruction in a two-phase static coordinate system based on the reactive power compensation instruction;

[0017] S6, adjusting the inverter output voltage instruction based on the current instruction in the two-phase static coordinate system and in combination with the inverter output current.

[0018] Further, in the S2, the inverter output voltage amplitude is represented as:

[0019]

[0020] wherein V represents the inverter output voltage amplitude; v α represents the inverter output voltage component instruction on the α axis; v β represents the inverter output voltage component instruction on the β axis.

[0021] Further, the high-gain robust voltage controller is represented as:

[0022]

[0023] wherein:

[0024] e = V N -V

[0025]

[0026] wherein u represents the control rate; k represents the voltage controller gain; e represents the voltage amplitude deviation between the inverter output voltage amplitude V and the rated voltage amplitude V N ; ρ(V) represents the voltage control function; c1, c2 and c3 all represent intermediate variable parameters in the formula; represents the upper limit of the intermediate variable parameter c3; ξ represents the voltage convergence speed factor; κ v represents the voltage scaling coefficient; κ i represents the current scaling coefficient; Q represents the output reactive power; C represents the virtual capacitance; k G represents the reactive overload capacity coefficient; k G Q N represents the upper limit of the inverter output reactive power.

[0027] Further, the reactive power compensation instruction is represented as:

[0028]

[0029] wherein Q v represents the reactive power compensation instruction; C represents the virtual capacitance; V represents the inverter output voltage amplitude; κ vrepresents a voltage scaling factor; κ i represents a current scaling factor; u represents a control rate.

[0030] Further, the S5 is represented as:

[0031]

[0032] wherein, represents an inverter output current component instruction in the α-axis; represents an inverter output current component instruction in the β-axis; v αβ represents an inverter output voltage instruction in a two-phase stationary coordinate system; ||v αβ || 2 represents a 2-norm of the inverter output voltage instruction v αβ , and v α represents an inverter output voltage component instruction in the α-axis; v β represents an inverter output voltage component instruction in the β-axis; P ref represents an active power reference instruction; Q v represents a reactive power compensation instruction.

[0033] Further, the S6 specifically includes:

[0034] S61, difference between the current instruction in the two-phase stationary coordinate system and the measured inverter output current, combined with a current scaling factor κ i and a rotation matrix J transformation, to obtain an α-axis input signal u1 and a β-axis input signal u2; represented as:

[0035]

[0036] wherein, represents a coordinate rotation transformation angle; i α represents an inverter output current component in the α-axis; i β represents an inverter output current component in the β-axis; represents an inverter output current component instruction in the α-axis; represents an inverter output current component instruction in the β-axis;

[0037] S62, input the α-axis input signal u1 and the β-axis input signal u2 into an AH type oscillator to generate a virtual capacitor voltage v C and a virtual inductor current i L ; represented as:

[0038]

[0039] wherein, L represents a virtual inductance; C represents a virtual capacitance; epsilon represents an impedance proportionality coefficient, and

[0040] v m represents a nonlinear voltage source, and xi represents a voltage convergence speed factor; X N represents a nominal amplitude of the oscillator limit cycle; ||x|| 2 represents a 2-norm of x, and omega N represents a nominal angular frequency, and i m represents a nonlinear current source, and

[0041] S63, in combination with the S61-S62, a dynamic characteristic equation of the inverter output voltage instruction is generated; represented as:

[0042]

[0043] wherein, represents an inverter output voltage component instruction rate of change in the alpha axis; represents an inverter output voltage component instruction rate of change in the beta axis;

[0044] S64, according to the inverter output voltage component instruction rate of change and the inverter output voltage instruction is adjusted to generate a new inverter output voltage instruction.

[0045] Further, based on Lyapunov's second law, the global uniform ultimate boundedness of the system under the action of the high-gain robust voltage controller is proved.

[0046] Via the technical solution described above, compared with the prior art, the present application provides an AH-VOC inverter high-gain robust voltage control method considering reactive power limitation, which has the following beneficial effects:

[0047] In view of the problem that the port voltage fluctuates greatly when the load of the existing AH-VOC inverter is switched, the present application configures a high-gain robust voltage controller to dynamically compensate the reactive power to maintain the inverter output voltage; compared with the original AH-VOC inverter, when the high-gain robust voltage controller designed based on the present application is used for voltage control, the fluctuation of the inverter port voltage when the load is switched can be reduced; compared with the PI voltage controller, the robustness and stability of the voltage control in the present application are better.

[0048] The technical solutions of the present application will be described in further detail below with the aid of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to make the technical solutions of the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the accompanying drawings in the following description only aim at the embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the provided drawings.

[0050] Figure 1 The high-gain robust voltage controller design flowchart provided for the embodiments of the present application.

[0051] Figure 2 The Q-V characteristic curve diagram of the AH-VOC inverter provided for the embodiments of the present application.

[0052] Figure 3 The high-gain robust voltage control method flowchart of the AH-VOC inverter considering reactive power limitation provided for the embodiments of the present application.

[0053] Figure 4 The high-gain robust voltage control method framework diagram of the AH-VOC inverter considering reactive power limitation provided for the embodiments of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.

[0055] In view of the problem that the port voltage fluctuates greatly when the load is switched in the existing AH-VOC inverter, the embodiments of the present application provide a high-gain robust voltage controller. Figure 1 As shown in the figure, the design method of the high-gain robust voltage controller specifically includes the following steps:

[0056] P1: establishing a mathematical model of the AH-VOC controller in the polar coordinate system;

[0057] P2: analyzing the influence of the load on the amplitude of the port voltage of the AH-VOC inverter;

[0058] P3: combining the output voltage characteristics and the reactive power constraint, designing a high-gain robust voltage controller;

[0059] P4: combining the Lyapunov second law to prove the stability of the proposed voltage controller;

[0060] Next, the above steps P1-P4 are described in detail, respectively.

[0061] In the above step P1, the mathematical model of the AH-VOC controller in the polar coordinate system is established; including:

[0062] The AH-VOC inverter is a grid-connected inverter using the Andrew-Hoff type virtual oscillator control strategy. When the inverter parameters are initialized, the given active power reference instruction P ref and the reactive power reference instruction Q ref are converted into current instructions in the two-phase stationary coordinate system by formula (1) Specifically, the inverter output current component instruction in the α-axis and the inverter output current component instruction in the β-axis are expressed as:

[0063]

[0064] Where, v αβ represents the inverter output voltage instruction in the two-phase stationary coordinate system; ||v αβ || 2 represents the 2-norm of the voltage instruction value v αβ , and Where, v α represents the inverter output voltage component instruction in the α-axis; v β represents the inverter output voltage component instruction in the β-axis;

[0065] The current instruction value is subtracted from the inverter output current i αβ , combined with the current scaling factor κ i and the rotation matrix J transformation, to obtain the α-axis input signal u1 and the β-axis input signal u2; expressed as:

[0066]

[0067] Where, represents the coordinate rotation transformation angle, which is related to the output characteristics of the AH-VOC inverter; i α represents the inverter output current component in the α-axis; i β represents the inverter output current component in the β-axis;

[0068] The α-axis input signal u1 and the β-axis input signal u2 are input into the AH type oscillator, and the oscillator oscillation generates a virtual capacitor voltage v C and a virtual inductor current i L ; expressed as:

[0069]

[0070] Where L represents the virtual inductance; C represents the virtual capacitance; and ε represents the impedance proportionality coefficient.

[0071] v m This represents a nonlinear voltage source, and ξ represents the voltage convergence rate factor; X N Indicates the rated amplitude of the oscillator limit cycle; ||x|| 2 Let x denote the 2-norm of x, and ω N Indicates the rated angular frequency, and i m This represents a nonlinear current source, and

[0072] Combined with voltage scaling factor κ v Obtain the inverter output voltage component command v on the α axis. α and the inverter output voltage component command v on the β axis β ; indicates as:

[0073] v α =κ v v C

[0074] v β =κ v εi L

[0075] Wherein, the current scaling factor κ i and voltage scaling factor κ v With respect to the rated voltage amplitude V of the inverter N and rated capacity S N The relationships are shown in equations (4) and (5) respectively:

[0076]

[0077] κ v =V N (5)

[0078] To further study the output characteristics of the AH-VOC inverter, it is assumed that the external line impedance of the inverter is mainly inductive, and let... The combined equations (1) and (3) can be used to define the inverter output voltage command v in a two-phase stationary coordinate system. αβ The dynamic characteristics are expressed as equation (6):

[0079]

[0080] in, This represents the rate of change of the inverter output voltage component commanded along the α axis; represents the inverter output voltage component command rate of change in the β axis; represents the current reference value in the β axis; represents the current reference value in the α axis;

[0081] As can be seen from formula (6), unlike droop control and virtual synchronous machine control, the dynamic characteristics of the AH-VOC inverter are a strongly coupled nonlinear equation, and it is difficult to directly analyze the relationship between the inverter output voltage amplitude and phase and power; therefore, the inverter output voltage amplitude V and voltage phase angle θ are defined as shown in formula (7) and formula (8):

[0082]

[0083] The derivatives of formula (7) and formula (8) are taken, and formula (6) is substituted, so that the voltage amplitude dynamic characteristics and the voltage phase angle dynamic characteristics of the inverter output in the polar coordinate system can be respectively represented as formula (9) and formula (10):

[0084]

[0085] wherein, represents the time rate of change of the inverter output voltage amplitude V; represents the time rate of change of the inverter output voltage phase angle θ, also known as the inverter output voltage angular frequency; Q represents the output reactive power; and P represents the output active power.

[0086] As can be seen from formula (9) and (10), on the one hand, under the condition of a certain rotation angle, the inverter output voltage amplitude is related to the output reactive power Q, and the inverter output voltage angular frequency is related to the output active power P. On the other hand, compared with the linear relationship of the traditional droop control, the AH-VOC inverter has a nonlinear term in the Q-V characteristic, and there is a relationship between the voltage amplitude characteristic and the voltage frequency characteristic.

[0087] In the above step P2, the influence of the load on the AH-VOC inverter voltage amplitude is analyzed; including:

[0088] Next, the influence of the load on the AH-VOC inverter terminal voltage amplitude is analyzed, and for the purpose of simplifying the analysis, the above voltage amplitude dynamic characteristic equation is expressed in the per-unit form. The inverter output voltage amplitude per-unit V pu and the reactive power per-unit Q pu are respectively defined as formula (11) and formula (12):

[0089]

[0090] Therefore, the dynamic characteristics of the inverter output terminal voltage per-unit V pu can be represented as formula (13):

[0091]

[0092] wherein, represents the rate of change of the inverter output voltage amplitude normalized value V pu ; and represents the normalized value of the reactive power instruction;

[0093] According to formula (13), the Q-V characteristic of the inverter can be divided into two independent parts: the first part makes the output voltage amplitude close to the rated value V N , and the second part adjusts the voltage amplitude according to the deviation between the reference value and the actual value of the reactive power of the inverter. The Q-V characteristic curve of the AH-VOC inverter is plotted as shown in Figure 2 , from which it can be seen that, under the condition that the given reactive power instruction value is 0, the operating characteristic of the inverter is shown by the black solid line in the figure, and ideally, when the carried reactive load is 0, the output voltage amplitude of the inverter can be stabilized at 1 p.u.

[0094] When the inverter carries the rated reactive load, it corresponds to the a1 point on the original operating characteristic curve. Let The normalized value of the output voltage amplitude of the inverter at steady state can be represented by formula (13), and analysis shows that, under the condition that the control parameters C and ξ are constant, when the given reactive power instruction value is 0, the inverter carrying the reactive load will cause the voltage of the inverter to deviate from the rated value. When the given reactive power instruction value is not 0, when the reactive load is increased, the deviation between the actual value and the reference value of the reactive power causes the output voltage amplitude of the inverter to decrease and deviate from the rated value.

[0095]

[0096] Therefore, as shown in formula (15), the reactive compensation amount Q v is introduced, the voltage characteristic curve is shifted upward from the original black solid line to the green dashed line, and the operating point of the inverter can be shifted from a1 to b1, so that the compensation of the steady-state voltage deviation can be realized.

[0097]

[0098] In the above step P3, a high-gain robust voltage controller is designed in combination with the output voltage characteristic and the reactive constraint; including:

[0099] As can be seen from formula (9), unlike the linear relationship of the droop inverter output Q-V characteristic curve, there is a first-order nonlinear relationship between the output reactive power and the terminal voltage amplitude of the AH-VOC inverter. For simplicity of analysis, parameters c1, c2, and c3 are defined as shown in formula (16).

[0100]

[0101] where c1, c2 and c3 are intermediate variable parameters in the formula; ξ represents a voltage convergence speed factor; κ v represents a voltage scaling coefficient; κ i represents a current scaling coefficient; Q represents output reactive power; and C represents a virtual capacitance.

[0102] On one hand, given the AH-VOC inverter control parameters ξ and V N , it can be determined that the values of c1 and c2 are positive real numbers. On the other hand, since the specific size of the reactive load carried by the inverter during operation is usually difficult to accurately estimate, c3 is an uncertain value. Considering the limitation of the hardware structure of the power electronic device, the reactive overload capacity of the inverter is defined as k G , and the upper limit of the output reactive power of the inverter is k G Q N . Thus, the upper limit of the parameter c3 can be represented as formula (17).

[0103]

[0104] where k G represents a reactive overload capacity coefficient; k G Q N represents the upper limit of the output reactive power of the inverter.

[0105] A nonlinear function f(V) = c1V - c2V 3 -c3 V related to the output voltage of the inverter is defined, and by introducing a control rate u, formula (9) can be rewritten as formula (18) in combination with formula (14):

[0106]

[0107] According to the triangle inequality, |f(V)| satisfies the relationship shown in formula (19):

[0108]

[0109] Define the intermediate function , then |f(V)| < p(V). To compensate for the voltage deviation, in combination with the voltage amplitude deviation e = V N -V between the output voltage amplitude V of the inverter and the rated voltage amplitude V N , a high-gain robust voltage controller shown in formula (20) is designed:

[0110]

[0111] On this basis, the derivative of the voltage amplitude deviation e is represented as formula (21):

[0112]

[0113] In the above step P4, the stability of the proposed voltage controller is proved by combining Lyapunov's second law; specifically including:

[0114] Next, the stability of the proposed voltage controller is proved by combining Lyapunov's second law. The Lyapunov function is selected as S = e 2 / 2, then S is a positive definite (PD) function. Taking the derivative, it can be known that, Substituting formula (19), then can be represented as formula (22). At the same time, it can be known from formula (19) that formula (23) is established. Thus, formula (24) can be obtained.

[0115]

[0116] -ef(V)≤|e||f(V)|≤|e|ρ(V) (23)

[0117]

[0118] When ρ(V)|e|>ε, it can be obtained that When ρ(V)|e|≤ε, according to the differential inequality theory, when the theoretical value of the voltage amplitude error e satisfies the condition shown in formula (25), it has . That is, under the stable state of the system, the voltage error is bounded, and the global uniform ultimate boundedness of the system is proved. Further, the control rate u can be converted into the reactive power compensation instruction Q v by formula (26).

[0119]

[0120] In summary, it is the design and proof process of the high-gain robust voltage controller of the application. Based on the high-gain robust voltage controller, the application provides an AH-VOC inverter high-gain robust voltage control method considering reactive power limitation, as shown in Figure 3 and Figure 4 , including the following steps:

[0121] S1, in the running process of the AH-VOC inverter, the inverter output voltage instruction v αβ in the two-phase static coordinate system is obtained; specifically including the inverter output voltage component instruction v α on the α axis and the inverter output voltage component instruction v β on the β axis;

[0122] S2, based on the inverter output voltage instruction v αβ , the inverter output voltage amplitude V is approximately calculated by the above formula (7);

[0123] S3, the inverter output voltage amplitude V is input into the configured high-gain robust voltage controller, and the control rate u is calculated by combining the above formula (20);

[0124] S4, based on the control rate u, the reactive power compensation instruction Q v is obtained by combining the above formula (26);

[0125] S5, the reactive power compensation instruction Q v is substituted into the reactive power reference instruction in the above formula (1) to generate the current instruction in the two-phase static coordinate system; specifically including the inverter output current component instruction in the α axis and the inverter output current component instruction in the β axis, that is, represented as:

[0126]

[0127] S6, based on the current instruction in the two-phase static coordinate system, the inverter output voltage instruction is adjusted in combination with the inverter output current; specifically including:

[0128] S61, during the operation of the inverter, the three-phase output current i abc is detected, and abc-αβ transformation is performed on it through the coordinate transformation module to obtain the inverter output current components i α and i β on the αβ axis; according to the above formula (2), the current instructions and in the two-phase static coordinate system are respectively subtracted from the measured inverter output currents i α and i β , and the current scaling factor κ i and the rotation matrix J transformation are combined to obtain the α axis input signal u1 and the β axis input signal u2;

[0129] S62, according to the above formula (3), the α axis input signal u1 and the β axis input signal u2 are input into the AH type oscillator to generate the virtual capacitor voltage v C and the virtual inductor current i L ;

[0130] S63, in combination with S61-S62, the dynamic characteristic equation of the inverter output voltage instruction as shown in formula (6) is generated to obtain the inverter output voltage component instruction change rate and the inverter output voltage component instruction change rate on the β axis

[0131] S64, according to the inverter output voltage component instruction change rate and The inverter output voltage instruction is adjusted to generate a new inverter output voltage instruction; thereby maintaining the stability of the AH-VOC inverter output voltage in the case of load switching.

[0132] Compared with the original AH-VOC inverter, when the high-gain robust voltage controller designed based on the application is used for voltage control, the fluctuation of the inverter terminal voltage during load switching can be reduced; compared with the PI voltage controller, the robustness and stability of the voltage control in the application are better.

[0133] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0134] The above description of the disclosed embodiments enables those skilled in the art to carry out or use the application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high gain robust voltage control method for AH-VOC inverters considering reactive power limits, characterized by, The method comprises the following steps: S1, obtaining an inverter output voltage instruction in a two-phase stationary coordinate system during operation of an AH-VOC inverter; S2, obtaining an inverter output voltage amplitude based on the inverter output voltage instruction; S3, inputting the inverter output voltage amplitude into a high-gain robust voltage controller configured to output a control rate; S4, obtaining a reactive power compensation instruction based on the control rate; S5, generating a current instruction in the two-phase stationary coordinate system based on the reactive power compensation instruction; S6, adjusting the inverter output voltage instruction based on the current instruction in the two-phase stationary coordinate system and in combination with an inverter output current.

2. The AH-VOC inverter high-gain robust voltage control method considering reactive power limit according to claim 1, wherein, In the S2, the inverter output voltage amplitude is represented as: where V represents the inverter output voltage amplitude; v α represents the inverter output voltage component command on the α axis; v β represents the inverter output voltage component command on the β axis.

3. The AH-VOC inverter high-gain robust voltage control method considering reactive power limit according to claim 1, wherein, The high-gain robust voltage controller is represented as: Wherein: e = V N -V where u represents the control rate; k represents the voltage controller gain; e represents the voltage magnitude deviation between the inverter output voltage magnitude V and the rated voltage magnitude V N ; p(V) represents the voltage control function; c1, c2, and c3 all represent intermediate variable parameters in the formula; represents the upper limit of the intermediate variable parameter c3; ξ represents the voltage convergence speed factor; κ v represents the voltage scaling coefficient; κ i represents the current scaling coefficient; Q represents the output reactive power; C represents the virtual capacitance; k G represents the reactive overload capability coefficient; k G Q N represents the upper limit of the inverter output reactive power.

4. The AH-VOC inverter high-gain robust voltage control method with reactive power limit consideration according to claim 1, wherein, The reactive power compensation instruction is represented as: where Q v represents the reactive power compensation instruction; C represents the virtual capacitance; V represents the inverter output voltage amplitude; κ v represents the voltage scaling coefficient; κ i represents the current scaling coefficient; u represents the control rate.

5. The AH-VOC inverter high-gain robust voltage control method with reactive power limit consideration according to claim 1, wherein, The S5 is represented as: wherein represents the inverter output current component command in the α-axis; represents the inverter output current component command in the β-axis; αβ represents the inverter output voltage command in the two-phase stationary coordinate system; αβ 2 represents the inverter output voltage command v αβ , and α represents the inverter output voltage component command in the α-axis; β represents the inverter output voltage component command in the β-axis; ref represents the active power reference command; v represents the reactive power compensation command.​​ 6. The AH-VOC inverter high-gain robust voltage control method with reactive power limit consideration according to claim 1, wherein, The S6 specifically comprises: S61, difference between the current command in the two-phase stationary coordinate system and the measured inverter output current, combined with the current scaling factor K i and the rotation matrix J transformation, the input signal u1 and the input signal u2 of the β axis are obtained; represented as: wherein, represents a coordinate rotation transformation angle; i α represents an inverter output current component on the α axis; i β represents an inverter output current component on the β axis; represents an inverter output current component on the α axis command; represents an inverter output current component on the β axis command; S62, inputting the α-axis input signal u1 and the β-axis input signal u2 into an AH-type oscillator to generate a virtual capacitor voltage v C and a virtual inductor current i L ; represented as: where L represents a virtual inductance; C represents a virtual capacitance; ε represents an impedance proportionality factor, and v m represents a non-linear voltage source, and ξ represents a voltage convergence speed factor; X N represents a nominal amplitude of the oscillator limit cycle; ||x|| 2 represents the 2-norm of x, and ω N represents a nominal angular frequency, and i m represents a non-linear current source, and S63, in combination with the S61-S62, generating a dynamic characteristic equation of the inverter output voltage instruction; represented as: wherein, represents an inverter output voltage component command rate of change in the α axis; represents an inverter output voltage component command rate of change in the β axis; S64, varying the inverter output voltage component command in accordance with the rate of change of the inverter output voltage and adjusting the inverter output voltage command to generate a new inverter output voltage command.

7. The AH-VOC inverter high-gain robust voltage control method with reactive power limit consideration according to claim 1, wherein, Based on Lyapunov's second law, it is proved that the system under the action of the high-gain robust voltage controller is globally uniformly ultimately bounded.

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