A globally asymptotically stable transient voltage stabilizer grid forming control method and system

Abstract

The application provides a globally asymptotically stable transient voltage stabilizer network control method and system, in particular to a globally asymptotically stable transient voltage stabilizer network control method, wherein the control method comprises: establishing an alternating current feedback module and a direct current voltage feedforward module; updating an oscillator state vector according to alternating current sampling of the alternating current feedback module and direct current voltage sampling of the direct current voltage feedforward module; and calculating an inverter voltage instruction according to the updated oscillator state vector and a transient voltage stabilizer network control algorithm of the transient voltage stabilizer. The application can stabilize the DVS system to provide voltage support under large disturbance, and can inhibit oscillation and overcurrent caused by multi-machine interaction.

Description

Technical Field

[0001] This invention belongs to the field of new energy grid connection technology, and specifically relates to a global progressively stable transient voltage stabilizer grid construction control method and system. Background Technology

[0002] Static Var Generators (SVG), as a type of power electronic dynamic reactive power compensation device, offer a potential solution to voltage fluctuations caused by renewable energy grid integration. However, SVGs, based on grid-following control, are susceptible to instability in scenarios with weak grid strength and significant voltage disturbances. Furthermore, the constant current characteristics of grid-following control during fault recovery can lead to transient overvoltages. Grid-following control, as a voltage source control method, can address the instability and inaccuracy issues inherent in dynamic voltage compensation under grid-following mode, thereby leveraging the fast response characteristics of power electronic converters to provide robust voltage support.

[0003] Existing grid-type control strategies make relatively ideal assumptions about the DC-side voltage model. However, the DC bus capacitor of a real inverter has limited energy storage. It is necessary to consider the transient characteristics of the energy balance of the DC bus capacitor during voltage support. At the same time, during voltage support, the transient interaction characteristics between multiple grid-type devices may lead to divergent oscillations. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a global asymptotically stable transient voltage stabilizer network control method, wherein the control method includes:

[0005] Establish an AC current feedback module and a DC voltage feedforward module;

[0006] The oscillator state vector is updated based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module.

[0007] Based on the updated oscillator state vector and the transient voltage stabilizer network control algorithm, the inverter voltage command is calculated.

[0008] Furthermore, the transient voltage stabilizer network control algorithm is expressed by the following formula:

[0009]

[0010] in, It is the inverter voltage command, v α and v β Here, α and β are the inverter voltage command components, η is the active synchronization control parameter, μ is the amplitude control parameter, and q is the amplitude control parameter. *This indicates the set value for reactive power amplitude. For overcurrent suppression, κ is the intermediate variable of voltage amplitude, ω is the line impedance parameter angle, J is the virtual angular velocity of the oscillator, and φ(υ) is the two-dimensional rotation matrix. αβ ) indicates that for v αβ Voltage amplitude control function, i is the inverter output current. α and i β These are the α-axis and β-axis components of the inverter output current, respectively.

[0011] Furthermore, φ(v αβ This can be expressed by the following formula:

[0012]

[0013] Where ||·|| represents the Euclidean norm of the vector, and υ * The set value for AC voltage amplitude.

[0014] Furthermore, the virtual angular velocity ω is expressed by the following formula:

[0015]

[0016] Among them, v dc ω is the DC bus voltage of DVS. n k is the rated frequency of the power grid. dc These are DC voltage control parameters. This indicates the set value for the DC voltage amplitude.

[0017] Furthermore, the intermediate voltage amplitude variable involved in overcurrent suppression This can be expressed by the following formula:

[0018]

[0019] Among them, I max k is the threshold parameter for overcurrent suppression. oc Here, ||·|| represents the overcurrent suppression control parameter, and ||·|| denotes the Euclidean norm of the vector.

[0020] Furthermore, the line impedance parameter angle κ is expressed by the following formula:

[0021] κ = tan -1 (ω n L g / R g )

[0022] Where, ω n R is the rated frequency of the power grid. g and L g These are the resistance and inductance parameters of the circuit, respectively.

[0023] Furthermore, the transient voltage stabilizer network control method also includes:

[0024] Current inner-loop control based on virtual admittance is used to enhance the inverter's adaptability to different line impedance parameters.

[0025] Furthermore, current inner-loop control is performed, including:

[0026] Calculate the phase angle θ of the oscillator, where θ is calculated using the following formula:

[0027] θ=tan -1 (v β / v α )

[0028] Among them, v α and v β These are the α-axis and β-axis components of the inverter voltage command.

[0029] Furthermore, current inner-loop control also includes:

[0030] Calculate the inner loop current command in, The calculation is performed using the following formula:

[0031]

[0032] in, This is a current inner loop command. and These are the α-axis and β-axis components of the inner current loop command. For inverter voltage command, v α and υ β These are the α-axis and β-axis components of the inverter voltage command. For grid-side voltage measurement, V gα and B gβ For the α-axis and β-axis components of the grid-side voltage measurement, I is the two-dimensional identity matrix, J is the two-dimensional rotation matrix, r and x are the virtual resistance and virtual reactance, and Y is the virtual resistance and virtual reactance. αβ This is a virtual admittance.

[0033] Furthermore, current inner-loop control also includes:

[0034] The virtual resistance and virtual reactance are set to increase linearly with the inverter overcurrent to suppress overcurrent phenomena during the voltage support process.

[0035] Furthermore, the following formulas express that the virtual resistance r and virtual reactance x increase linearly with the inverter overcurrent:

[0036] r = r0 + k z，ocI oc

[0037] x = x0 + k z，oc I oc

[0038] Among them, I oc k represents the overcurrent value. z，oc is the virtual impedance overcurrent coefficient, r0 is the initial virtual resistance, and x0 is the initial virtual reactance.

[0039] Furthermore, I oc This can be expressed by the following formula:

[0040]

[0041] Among them, ||I dq || represents the output current amplitude of the inverter, I max This is the threshold parameter for overcurrent suppression.

[0042] Furthermore, current inner-loop control also includes:

[0043] The pulse width modulation (PWM) signal is obtained by performing coordinate transformation based on the phase angle θ.

[0044] Furthermore, the coordinate transformation is expressed by the following formula:

[0045]

[0046]

[0047] Where, x a x b x c x α x β x d and x q In this context, x represents a variable, subscripts α and β indicate a stationary two-dimensional coordinate system, subscripts a, b, and c indicate a stationary three-dimensional coordinate system, subscripts d and q indicate a rotating two-dimensional coordinate system, and θ is the phase angle of the oscillator.

[0048] On the other hand, the present invention also provides a globally asymptotically stable transient voltage stabilizer network control system, wherein the system includes:

[0049] The building block is used to establish the AC current feedback module and the DC voltage feedforward module;

[0050] The update unit is used to update the oscillator state vector based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module.

[0051] The calculation unit is used to calculate the inverter voltage command based on the updated oscillator state vector and the transient voltage stabilizer network control algorithm.

[0052] Furthermore, the system also includes:

[0053] The configuration unit is used for current inner-loop control based on virtual admittance to enhance the inverter's adaptability to different line impedance parameters.

[0054] Compared with the prior art, the present invention provides a global asymptotically stable transient voltage stabilizer network control method and system, which can enable the inverter to stably provide voltage support under large disturbances and suppress oscillations and overcurrents caused by multi-machine interaction (by suppressing overcurrents through virtual impedance).

[0055] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart of a global asymptotically stable transient voltage stabilizer network control method according to an embodiment of the present invention is shown;

[0058] Figure 2 The diagram shows a logic control block diagram corresponding to a global asymptotically stable transient voltage stabilizer network control method according to an embodiment of the present invention.

[0059] Figure 3 A logic control block diagram of current inner loop control according to an embodiment of the present invention is shown;

[0060] Figure 4 A structural diagram of a globally asymptotically stable transient voltage stabilizer network control system according to an embodiment of the present invention is shown. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] This invention provides a globally asymptotically stable transient voltage stabilizer network control method and a globally asymptotically stable transient voltage stabilizer network control system. The transient voltage stabilizer network control method can be implemented based on a global transient voltage stabilizer network control system.

[0063] The following describes a globally asymptotically stable transient voltage stabilizer network control method, such as... Figure 1 As shown, in this invention, a globally asymptotically stable transient voltage stabilizer network control method includes:

[0064] S1. Establish an AC current feedback module (i.e. Figure 2 AC current feedback and DC voltage feedforward module (i.e. Figure 2 DC voltage feedforward in the middle;

[0065] S2. Update the oscillator state vector based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module. The updated oscillator state vector consists of the oscillator virtual angular velocity ω and the intermediate variables of voltage amplitude.

[0066] S3. Based on the updated oscillator state vector and the Dynamic Voltage Stabilizer (DVS) network control algorithm, the inverter voltage command is calculated.

[0067] The above method for controlling the transient voltage stabilizer network mainly involves first sampling the AC current and DC voltage, and then updating the intermediate variables of the oscillator's virtual angular velocity ω and voltage amplitude. Finally, the inverter voltage command is calculated. In addition, in this invention, after the inverter voltage command is calculated, it can also be used as the input for the current inner loop control.

[0068] The transient voltage stabilizer network control method provided by the present invention will be described in detail below.

[0069] In some embodiments of the present invention, such as Figure 2 As shown, the AC current sampling method performed by the AC current feedback module is as follows:

[0070] If i αβ The Euclidean norm of a vector is calculated to be greater than or equal to I. max Then the inverter output current i αβ The squared value of the vector after Euclidean norm calculation and the overcurrent suppression threshold parameter I max The difference between the squared values ​​is then compared with the overcurrent suppression control parameter k. oc Multiply by the product and then add it to the set value v of the AC voltage amplitude. * The intermediate variable of voltage amplitude participating in overcurrent suppression is obtained by adding the squares of the values. If i αβ The Euclidean norm of a vector is less than I. max Then take the set value v of the AC voltage amplitude. * The square value is used as an intermediate variable for the voltage amplitude of overcurrent suppression.

[0071] The set value q of reactive power amplitude * Intermediate variable of voltage amplitude obtained above After performing the division operation, it is compared with the inverter voltage command v. αβ sum matrix Perform a product operation to obtain the first calculated value, and then multiply this first calculated value with the inverter output current i. αβ With matrix The product of the two products is then subtracted to obtain the second calculated value.

[0072] Set the AC voltage amplitude value v * The square value of the inverter voltage command v αβ The third calculated value is obtained by subtracting the square of the vector after calculating its Euclidean norm. This third calculated value is then compared with the set value v of the AC voltage amplitude. * The squared value divided by the inverter voltage command V αβ The product is then multiplied, and then multiplied again through the amplitude control parameter μ to obtain the fourth calculated value.

[0073] Add the second calculated value to the fourth calculated value to obtain the fifth calculated value.

[0074] In some embodiments of the present invention, such as Figure 2 As shown, the DC voltage sampling method performed by the DC voltage feedforward module is as follows:

[0075] The fifth calculated value is multiplied by the active synchronization control parameter η to obtain the sixth calculated value. The sixth calculated value is then multiplied by the inverter voltage command υ. αβ The final result of the transient voltage stabilizer network control algorithm is obtained by adding the product of the virtual angular velocity ω output by the DVS and the two-dimensional rotation matrix J. This refers to the differential component of the inverter voltage command. The inverter voltage command can be obtained from the inverter voltage command itself, and it can be expressed by the following formula:

[0076]

[0077] In the formula, vector It is the inverter voltage command, υ α and υ β Let α and β be the α and β components of the inverter voltage command, κ be the line impedance parameter angle, ω be the virtual angular velocity of the oscillator, and J be the two-dimensional rotation matrix, represented as: φ(υ αβ ) indicates that for v αβ Voltage amplitude control function.

[0078] In addition, in the above formula:

[0079] 1) Wherein, φ(v) αβ This can be expressed by the following formula:

[0080]

[0081] In the formula, the operator ||·|| represents the Euclidean norm of the vector.

[0082] 2) The virtual angular velocity ω is obtained in the following way:

[0083] DVS DC bus voltage v dc With the set value of DC voltage amplitude After subtraction, the DC voltage control parameter k is used. dc The product value is multiplied by the rated frequency ω of the power grid. n After addition, we obtain the virtual angular velocity ω, which is also the updated ω. This can be expressed by the following formula:

[0084]

[0085] 3) Among them, the intermediate variable of voltage amplitude involved in overcurrent suppression That is, update This can be expressed by the following formula:

[0086]

[0087] In the formula, I max k is the threshold parameter for overcurrent suppression. oc For overcurrent suppression control parameters, vector i is the inverter output current. α and i β These are the α-axis and β-axis components of the inverter output current, respectively.

[0088] 4) The line impedance parameter angle κ is expressed by the following formula:

[0089] κ = tan -1 (ω n L g / R g )

[0090] In the formula, R g and L g These are the resistance and inductance parameters of the circuit, respectively.

[0091] In addition, Figure 2 In the middle, parameter C dc For DC bus capacitance, V g The voltage amplitude of the external power grid (its value < 0), δ is the phase angle difference between the inverter's local voltage phasor and the external voltage phasor, and the inverter voltage command v αβ The value after performing Euclidean norm operations on a vector is less than δ. This represents the frequency domain integral operator.

[0092] This invention, through a DC voltage feedforward design, enables the network control algorithm to respond quickly to fluctuations in the DC bus voltage, thereby ensuring that the DC bus capacitor remains in an energy-balanced state while providing voltage support. Simultaneously, this design also allows the DVS to provide a portion of the virtual inertia matching the dynamic characteristics of the synchronous machine rotor through voltage fluctuations in the DC bus capacitor; its capacity is equivalent to... On the other hand, due to the AC current feedback design, the inverter's overcurrent transients are effectively suppressed, preventing overcurrent during voltage support from triggering inverter protection and causing shutdown. The oscillator-based control strategy (i.e., the transient voltage stabilizer grid control method) design ensures that the inverter's multi-machine AC grid-connected characteristics possess good global asymptotic synchronization stability. It is important to note that the core of this invention is to achieve stable voltage support characteristics for the DVS system under both strong and weak grid conditions through a globally asymptotically stable matched oscillator design, thus preventing inverter disconnection caused by multi-machine interactive instability under large disturbances.

[0093] On the other hand, in some embodiments of the present invention, the method further includes:

[0094] To enhance the inverter's adaptability to different line impedance parameters, it is possible to... Figure 2 v obtained αβ Then, current inner-loop control is designed based on virtual admittance. For details on current inner-loop control, please refer to... Figure 3 Specifically, it includes:

[0095] Calculate the phase angle θ of the oscillator, where θ is calculated using the following formula:

[0096] θ=tan -1 (v β / v α )

[0097] In the formula, v α and v β These are the α-axis and β-axis components of the inverter voltage command.

[0098] In the current inner loop control, the current inner loop command... It can be generated by the inverter voltage command v αβ With grid-side voltage measurement V gαβ After subtraction and virtual admittance Y αβ After multiplying, the product can be calculated using the following formula:

[0099]

[0100] Where, vector This is a current inner loop command. and For the α-axis and β-axis components of the current inner loop command, the vector... For inverter voltage command, υ α and v β The vector represents the α-axis and β-axis components of the inverter voltage command. For grid-side voltage measurement (i.e., grid-side voltage measurement value), V gα and V gβ The α-axis and β-axis components represent the grid-side voltage measurements. I is a two-dimensional identity matrix, J is a two-dimensional rotation matrix, and r and x are the virtual resistance and virtual reactance, respectively. The principle for setting the virtual impedance is to maintain a consistent equivalent impedance angle across the lines of the multi-machine interconnected network. Generally, the setting results tend to favor inductive networks, in which case the oscillator exhibits droop control characteristics for VQ.

[0101] like Figure 3 As shown, the current inner loop control is mainly implemented through a PI control method with dq axis decoupling, that is, based on the calculated current inner loop command. The phase angle θ of the oscillator is used to perform a coordinate transformation along the d-q axis, converting it into the d-axis and q-axis components of the inner current loop command. and Will The d-axis component I of the actual inverter current d After subtraction, the result is obtained by calculation using a PI controller. This first result is then compared with the d-axis component V of the grid-side voltage measurement. gd Summation (i.e., addition) is then performed and combined with the q-axis component I of the actual inverter current. q The d-axis component of the inverter output voltage modulation command is obtained by subtracting the product of the input and output voltage modulated by ...

[0102] Will The q-axis component I of the actual inverter current q After subtraction, the result is calculated using another PI controller to obtain the second result. This second result is then compared with the q-axis component V of the grid-side voltage measurement. gq Summing, then adding to the summation, and finally to the d-axis component I of the actual inverter current. d The difference between the product of the input voltage and the feedforward control gain ωL designed based on the filter inductor is used to obtain the q-axis component of the inverter output voltage modulation command.

[0103] The inner current loop control also includes: based on the phase angle θ of the oscillator and the above-mentioned... and A coordinate transformation along the dq axis is performed to obtain the pulse width modulation (PWM) signal. The coordinate transformation is expressed by the following formula:

[0104]

[0105]

[0106] Where, x a x b x c x α x β x d and x q In this context, x represents a general variable, subscripts α and β indicate a stationary two-dimensional coordinate system, subscripts a, b, and c indicate a stationary three-dimensional coordinate system, subscripts d and q indicate a rotating two-dimensional coordinate system, and θ is the phase angle of the oscillator.

[0107] Furthermore, in some embodiments of the present invention, setting a virtual impedance further suppresses overcurrent during the voltage support process. Therefore, the virtual resistance and virtual reactance can be set to increase linearly with the inverter overcurrent. Specifically:

[0108] The following formulas express the linear increase of virtual resistance r and virtual reactance x with inverter overcurrent:

[0109] r = r0 + k z，oc I oc

[0110] x = x0 + k z，oc I oc

[0111] In the formula, I oc k represents the overcurrent value. z，oc Let I be the virtual impedance overcurrent coefficient, r0 be the initial virtual resistance, and x0 be the initial virtual reactance. ocThis can be expressed by the following formula:

[0112]

[0113] In the formula, ||I dq || represents the inverter output current amplitude, I max This is the threshold parameter for overcurrent suppression.

[0114] In addition, in some embodiments of the present invention, the network control method further includes adjusting control parameters. Specifically, in the globally asymptotically stable transient voltage stabilizer network control method, parameter κ is generally taken near π / 2 based on the line parameters, at which point the DVS exhibits the droop characteristic of VQ. Parameter η corresponds to the active synchronization control parameter, typically selected between 2% and 5%. Parameter μ corresponds to the voltage amplitude correction coefficient (i.e., the voltage amplitude control parameter), typically selected between 1000 and 2000. The DC voltage control parameter k... dc The value is usually between 0.1 and 1.

[0115] On the other hand, such as Figure 4 As shown, the present invention also provides a globally asymptotically stable transient voltage stabilizer network control system, wherein the system includes:

[0116] The building block is used to establish the AC current feedback module and the DC voltage feedforward module;

[0117] The update unit is used to update the oscillator state vector based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module.

[0118] The calculation unit is used to calculate the inverter voltage command based on the updated oscillator state vector and the transient voltage stabilizer network control algorithm.

[0119] In addition, in some embodiments of the present invention, the system further includes:

[0120] The configuration unit is used for design current inner-loop control based on virtual admittance to enhance the inverter's adaptability to different line impedance parameters.

[0121] The functions and implementation methods of each unit in the global asymptotically stable transient voltage stabilizer network control system of the present invention correspond to the other functions and implementation methods of each step in the global asymptotically stable transient voltage stabilizer network control method of the present invention, therefore, they will not be repeated here.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A globally asymptotically stable transient voltage stabilizer network control method, wherein, The control method includes: Establish an AC current feedback module and a DC voltage feedforward module; The oscillator state vector is updated based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module. The inverter voltage command is calculated based on the updated oscillator state vector and the transient voltage stabilizer network control algorithm. The transient voltage stabilizer network control algorithm is expressed by the following formula: in, It is an inverter voltage command. and For inverter voltage command α shaft and β Axial components, To actively synchronize control parameters, For amplitude control parameters, q This indicates the set value for reactive power amplitude. As an intermediate variable of voltage amplitude participating in overcurrent suppression, The line impedance parameter angle. The virtual angular velocity of the oscillator. It is a two-dimensional rotation matrix. Indicates to Voltage amplitude control function, For inverter output current, and These are the inverter output currents. α shaft and β Axial components.

2. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 1, wherein, This can be expressed by the following formula: in, The Euclidean norm of a vector. The set value for AC voltage amplitude.

3. A method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 1 or 2, wherein, Virtual angular velocity This can be expressed by the following formula: in, This refers to the DC bus voltage of the DVS system. The rated frequency of the power grid. These are DC voltage control parameters. This indicates the set value for the DC voltage amplitude.

4. A global asymptotically stable transient voltage stabilizer network control method according to claim 1 or 2, wherein, Intermediate voltage amplitude variable involved in overcurrent suppression This can be expressed by the following formula: in, This is the threshold parameter for overcurrent suppression. These are overcurrent suppression control parameters. The Euclidean norm of a vector.

5. A global asymptotically stable transient voltage stabilizer network control method according to claim 1 or 2, wherein, Line impedance parameter angle This can be expressed by the following formula: in, The rated frequency of the power grid. and These are the resistance and inductance parameters of the circuit, respectively.

6. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 1, wherein, The transient voltage stabilizer network control method further includes: Current inner-loop control based on virtual admittance is used to enhance the inverter's adaptability to different line impedance parameters.

7. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 6, wherein, Perform current inner loop control, including: Calculate the phase angle of the oscillator ,in, Calculated using the following formula: in, and For inverter voltage command α shaft and β Axial components.

8. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 6, wherein, Inner-loop current control also includes: Calculate the inner loop current command ,in, The calculation is performed using the following formula: in, This is an inner loop current command. and For the inner loop command of the current α shaft and β Axial components, This is the inverter voltage command. and For inverter voltage command α shaft and β Axial components, For grid-side voltage measurement, and For grid-side voltage measurement α shaft and β Axial components, It is a two-dimensional identity matrix. It is a two-dimensional rotation matrix. and For virtual resistance and virtual reactance, This is a virtual admittance.

9. A global asymptotically stable transient voltage stabilizer network control method according to claim 8, wherein, Inner-loop current control also includes: The virtual resistance and virtual reactance are set to increase linearly with the inverter overcurrent to suppress overcurrent phenomena during the voltage support process.

10. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 8, wherein, The virtual resistance is represented by the following formulas. and virtual reactance The inverter overcurrent increases linearly: in, I oc This is the overcurrent value. The virtual impedance overcurrent coefficient, For the initial virtual resistance, This represents the initial virtual reactance.

11. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 8, wherein, I oc This can be expressed by the following formula: in, This refers to the output current amplitude of the inverter. This is the threshold parameter for overcurrent suppression.

12. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 6, wherein, Inner-loop current control also includes: According to the phase angle The coordinate transformation is performed to obtain the pulse width modulation (PWM) signal.

13. The method for controlling the network of a globally asymptotically stable transient voltage stabilizer according to claim 12, wherein, Coordinate transformation is expressed by the following formula: in, , , , , , and middle, Referencing variables, subscripts α , β In a stationary two-dimensional coordinate system, the subscript represents... a, b, c Indicates the subscript in a stationary three-dimensional coordinate system. d, q This indicates that in a rotating two-dimensional coordinate system, This represents the phase angle of the oscillator.

14. A globally asymptotically stable transient voltage stabilizer network control system, wherein, The system includes: The building block is used to establish the AC current feedback module and the DC voltage feedforward module; The update unit is used to update the oscillator state vector based on the AC current sampling performed by the AC current feedback module and the DC voltage sampling performed by the DC voltage feedforward module. The calculation unit is used to calculate the inverter voltage command based on the updated oscillator state vector and the transient voltage stabilizer network control algorithm. The transient voltage stabilizer network control algorithm is expressed by the following formula: in, It is an inverter voltage command. and For inverter voltage command α shaft and β Axial components, To actively synchronize control parameters, For amplitude control parameters, q This indicates the set value for reactive power amplitude. As an intermediate variable of voltage amplitude participating in overcurrent suppression, The line impedance parameter angle. The virtual angular velocity of the oscillator. It is a two-dimensional rotation matrix. Indicates to Voltage amplitude control function, For inverter output current, and These are the inverter output currents. α shaft and β Axial components.

15. A globally asymptotically stable transient voltage stabilizer network control system according to claim 14, wherein, The system also includes: The configuration unit is used for current inner-loop control based on virtual admittance to enhance the inverter's adaptability to different line impedance parameters.

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