Additional Damping Strategy and Parameter Tuning Method for Matched Control Network Converters

Abstract

This invention provides an additional damping strategy and parameter tuning method for a grid-connected converter based on matched control, belonging to the field of grid matched control technology. The method includes: determining circuit parameters and calculating the power angle coefficient and power base value through the circuit parameters; constructing an active power-frequency response model with added damping based on the power angle coefficient and power base value; solving the damping ratio expression and the natural oscillation frequency expression using the active power-frequency response model; and determining the control parameters in the active power-frequency response model based on preset constraints using the damping ratio expression and the natural oscillation frequency expression. Because a damping element is added to the mechanism control and a new transfer function model is obtained, the low-frequency oscillation problem is effectively alleviated. Furthermore, the values ​​of the control parameters can be calculated through parameter tuning, so that the response curve conforms to the given damping ratio and natural oscillation angular frequency.

Description

Technical Field

[0001] This invention relates to the field of power grid matching control technology, and in particular to an additional damping strategy and parameter tuning method for grid converters based on matching control. Background Technology

[0002] Driven by the strategic goals of "carbon peaking and carbon neutrality," the pace of energy transition has accelerated significantly, with new energy sources accounting for an increasingly larger share of the power system. However, the low inertia and weak damping characteristics of new energy sources pose a serious challenge to the stable operation of the power system. To address these challenges caused by the large-scale grid connection of new energy sources, research teams both domestically and internationally have proposed grid-based control strategies, aiming to enable converters to actively participate in the grid's regulation process. Depending on the specific implementation methods, grid-based control strategies can be further subdivided into several types, including droop control, virtual synchronous generator (VSG) control, and DC voltage matching control.

[0003] Both droop control and VSG control use output power as the controlled object, thus requiring a stable DC voltage as a prerequisite. Furthermore, the "demand" and "source" of power are not effectively unified. Therefore, based on the similarity and duality of the converter and synchronous machine in structure and characteristics, a matching relationship between the converter's DC capacitor voltage and the synchronous machine's rotor speed is established. The energy of the converter's DC bus capacitor is used to simulate the synchronous machine's rotor energy, thereby realizing the phase angle generation of the converter and ultimately achieving grid connection. This control is called the DC voltage synchronization control strategy, i.e., matching control. Compared to droop control and VSG control, matching control only requires tracking and measuring the DC bus voltage to achieve grid-connected control, making it more intuitive and flexible. It has high applicability for new energy sources without energy storage connecting to the grid via grid-connection.

[0004] However, in traditional matching control, the characteristics of the DC capacitor simulate the "inertia" of the synchronous generator rotor, but the damping inherent in the rotor itself cannot be simulated. This also makes this control scheme prone to unstable low-frequency oscillations. Summary of the Invention

[0005] This invention provides an additional damping strategy and parameter tuning method for a grid converter based on matched control, in order to solve the defect that matched control in the prior art is prone to causing low-frequency oscillations.

[0006] In a first aspect, the present invention provides an additional damping strategy and parameter tuning method for a matched-control grid converter, including:

[0007] Determining circuit parameters includes: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit for the additional damping stage; and determining the circuit parameters of the matching control circuit for the additional damping stage based on the power angle relationship of the grid-side converter output, including: the output voltage amplitude of the grid-side converter, the voltage amplitude at the grid connection point, and the line impedance between the two points.

[0008] The calculation of the power angle coefficient and frequency base value using the circuit parameters includes: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; and using the ratio of the product to the line impedance between the two points as the power angle coefficient.

[0009] Based on the power angle coefficient and the frequency base value, an active power-frequency response model with added damping matching control is constructed, including: determining the power relationship at both ends of the DC bus; combining the power relationship, the power angle coefficient, and the frequency base value, determining the angular frequency of the grid connection point, the grid-side converter, and the initial voltage phase of the grid connection point; inputting the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point into the transfer function model to obtain the active power-frequency response model with added damping matching control;

[0010] Using the active-frequency response model, the damping ratio expression and the natural oscillation frequency expression are solved, including: based on the active-frequency response model and the characteristics of the second-order transfer function, the damping ratio expression and the natural oscillation frequency expression are obtained;

[0011] Based on preset constraints, the control parameters in the active-frequency response model are determined using the damping ratio expression and the natural oscillation frequency expression.

[0012] The control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active-frequency response model includes:

[0013] ;

[0014] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0015] According to the present invention, an additional damping strategy and parameter tuning method for a grid-connected converter based on matched control is provided, wherein the active power-frequency response model is as follows:

[0016] ;

[0017] in, k p Indicates the power angle coefficient. oh B Indicates the base frequency value. K c This represents the DC voltage matching factor. K δ s represents the damping coefficient, s represents the Laplace operator, and C represents the DC capacitance. This represents the change in active power. This represents the change in angular frequency. This represents the active-frequency response model.

[0018] Secondly, the present invention also provides an additional damping strategy and parameter tuning device based on a matched control type grid converter, comprising:

[0019] The determination module is used to determine circuit parameters, including: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit for the additional damping stage; determining the circuit parameters of the matching control circuit for the additional damping stage based on the power angle relationship of the grid-side converter output, including: the output voltage amplitude of the grid-side converter, the voltage amplitude of the grid connection point, and the line impedance between the two points; calculating the power angle coefficient and frequency base value through the circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; and using the ratio of the product to the line impedance between the two points as the power angle coefficient.

[0020] A construction module is used to construct an active-frequency response model for matched control with added damping based on the power angle coefficient and the frequency base value. This includes: determining the power relationship between the two ends of the DC bus; combining the power relationship, the power angle coefficient, and the frequency base value to determine the angular frequency of the grid connection point, the initial voltage phase of the grid-side converter, and the grid connection point; and inputting the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point into the transfer function model to obtain the active-frequency response model for matched control with added damping.

[0021] The solution module is used to solve the damping ratio expression and the natural oscillation frequency expression using the active-frequency response model, including: obtaining the damping ratio expression and the natural oscillation frequency expression based on the active-frequency response model and the characteristics of the second-order transfer function;

[0022] The tuning module is used to determine the control parameters in the active-frequency response model based on preset constraints, using the damping ratio expression and the natural oscillation frequency expression; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active-frequency response model includes:

[0023] ;

[0024] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0025] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the additional damping strategy and parameter tuning method for a matched control type grid converter as described above.

[0026] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the additional damping strategy and parameter tuning method for a matched control type grid converter as described above.

[0027] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the additional damping strategy and parameter tuning method for a matched control type grid converter as described above.

[0028] This invention provides an additional damping strategy and parameter tuning method for a grid-connected converter based on matched control, comprising: determining circuit parameters and calculating the power angle coefficient and frequency base value through the circuit parameters; constructing an active-frequency response model with added damping based on the power angle coefficient and frequency base value; solving the damping ratio expression and the natural oscillation frequency expression using the active-frequency response model; determining the control parameters in the active-frequency response model based on preset constraints using the damping ratio expression and the natural oscillation frequency expression. Because a damping element is added to the mechanism control and a new transfer function model is obtained, the low-frequency oscillation problem is effectively alleviated, and the values ​​of the control parameters can be calculated through parameter tuning, so that the response curve conforms to the given damping ratio and natural oscillation angular frequency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this 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 this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a flowchart illustrating the additional damping strategy and parameter tuning method for a matched control grid converter provided in this embodiment.

[0031] Figure 2 This is a block diagram of the matching control structure of the additional damping element provided in this embodiment;

[0032] Figure 3 This is provided in this embodiment. Figure 2 PI controller structure diagram;

[0033] Figure 4 This embodiment provides that in oh n =5rad / s, g Schematic diagram of step response at 0.3;

[0034] Figure 5 This embodiment provides that in oh n =5rad / s, g Schematic diagram of the step response at a value of 0.707;

[0035] Figure 6 This is a schematic diagram of the structure of the additional damping strategy and parameter tuning device for the grid converter based on matched control provided in this embodiment;

[0036] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this embodiment. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0038] Figure 1This is a flowchart illustrating the additional damping strategy and parameter tuning method for a matched control network converter provided in this embodiment.

[0039] like Figure 1 As shown, the additional damping strategy and parameter tuning method for a matched control grid converter provided in this embodiment of the invention mainly includes the following steps:

[0040] 101. Determine the circuit parameters, and calculate the power angle coefficient and frequency base value using the circuit parameters.

[0041] In a specific implementation process, when the frequency changes, it is easy to cause low-frequency oscillations in the active power response. Therefore, a proportional element is added to the phase angle generation stage, so that the phase angle generation process changes to (1):

[0042] (1)

[0043] in, and Output phase angle of grid-side converter The two components. K δ The damping coefficient is... oh B Indicates the base frequency value. oh It is the actual output angular frequency of the converter, i.e., the controlled object, and s represents the Laplace operator, which is used as an additional damping element for matching control.

[0044] The improved control structure block diagram is as follows: Figure 2 As shown, where, V dc This is the actual value of the DC bus voltage. V dc_ref These are reference values ​​for the DC bus voltage, all in per-unit format. K c This is the DC voltage matching factor. oh 0 is the reference value for angular frequency. oh It is the actual output angular frequency of the converter, i.e., the controlled object.

[0045] The structure of a PI controller is as follows: Figure 3 As shown, an additional damping element is therefore added to the matching control. The circuit parameters of the matching control circuit with the additional damping element can then be determined based on the power angle relationship of the grid-side converter output, including the output voltage amplitude of the grid-side converter. E out Voltage amplitude at grid connection point U g and the line impedance between two points X d wait.

[0046] Then, the power angle coefficient is calculated through circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude at the grid connection point; using the ratio of the product to the line impedance between the two points as the power angle coefficient, such as (2):

[0047] k p = (2)

[0048] in, E out This indicates the output voltage amplitude of the grid-side converter. U g Indicates the voltage amplitude at the grid connection point. X d This represents the impedance of the line between two points. Frequency base value. oh B Take 100π rad / s, and the calculation method is as follows: oh B =2π f B , f B The reference frequency for the power grid is 50Hz.

[0049] 102. Based on the power angle coefficient and frequency base value, construct an active-frequency response model for matched control with added damping.

[0050] Based on the matching control of the additional damping element and the circuit relationship, a small-signal model can be constructed to analyze its active power response mechanism. The specific steps are as follows:

[0051] The power relationship between the two ends of the DC bus is (3):

[0052] (3)

[0053] Where C represents DC capacitance, V dc This represents the actual value of the DC bus voltage. P m The active power output of the machine-side converter is... P e Input active power to the grid-side converter. The current flowing through the DC capacitor, This is the power on the capacitor. The fluctuation range is extremely small, but the fluctuation speed is relatively high. It can be approximated as a constant, but its derivative can be regarded as a variable. Its Laplace transform yields (4):

[0054] (4)

[0055] Furthermore, considering the power angle relationship of the grid-side converter output (5):

[0056] (5)

[0057] in, E out This refers to the output voltage amplitude of the grid-side converter. U g The voltage amplitude at the grid connection point. X d The impedance of the line between the two points. d For the output phase of the grid-side converter, i This represents the phase of the grid voltage. All values ​​are per unit.

[0058] Will Write as a constant k p , denoted as the work angle coefficient.

[0059] The small-signal model of the matched control with added damping element is obtained by applying the small-signal analysis method to equation (5), as shown in equation (6):

[0060] (6)

[0061] in, oh g It is the angular frequency of the power grid connection point. and Let be the initial voltage phases of the grid-side converter and the grid connection point, respectively. Simplifying the above equation, let... Then, rearrange equation (6) to obtain the active-frequency response model, as shown in (7):

[0062] (7)

[0063] in, k p Indicates the power angle coefficient. oh B Indicates the base frequency value. K c This represents the DC voltage matching factor. K δ s represents the damping coefficient, s represents the Laplace operator, and C represents the DC capacitance. This represents the change in active power. This represents the change in angular frequency. This represents the active-frequency response model.

[0064] 103. Using the active-frequency response model, solve for the damping ratio expression and the natural oscillation frequency expression.

[0065] Parameter tuning is performed based on matched control with added damping. It is assumed that when the grid frequency changes, the natural oscillation angular frequency should be such that during the converter's active power response, the angular frequency of the natural oscillation should be... oh n Damping ratio g To achieve a certain range, the control parameter tuning process is as follows (8):

[0066] (8)

[0067] Comparing equations (7) and (8), we can see that the matched control transfer function with damping is the classical second-order transfer function with a differential element. Based on the active-frequency response model and the characteristics of the second-order transfer function, we can then obtain the damping ratio expression and the natural oscillation frequency expression (9):

[0068] (9)

[0069] in, k p The work angle coefficient, K c This is the DC voltage matching factor. oh B The base value of frequency. K δ Where C is the damping coefficient and C represents the DC capacitance. oh n The natural oscillation angular frequency, g is the damping ratio.

[0070] 104. Based on preset constraints, use the damping ratio expression and the natural oscillation frequency expression to determine the control parameters in the active-frequency response model.

[0071] Combining the constraints, including the given natural oscillation angular frequency and damping ratio requirements, transforming (9) yields the control parameters in the active-frequency response model. K c and K δ For example (10):

[0072] (10)

[0073] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh BIndicates the base frequency value. g This indicates the damping ratio.

[0074] For the parameters in equation (10) above, the power angle coefficient k p Based on circuit parameters: E out , U g , X d Joint decision, oh B The base frequency value is taken as 100π rad / s, and its calculation method is as follows: oh B =2π f B , f B The grid reference frequency is 50Hz. C is the DC capacitor, both of which are known quantities, therefore the control parameters... K c and K δ Only by oh n and g Decision. Confirmation. oh n and g The value of the control parameter can be used to calculate the value of the control parameter.

[0075] By analyzing the matched control mechanism, a damping element is added, resulting in a new transfer function, i.e., the active-frequency response model, which effectively alleviates the low-frequency oscillation problem. Furthermore, through parameter tuning, the values ​​of the control parameters can be accurately calculated, ensuring that the response curve conforms to the given damping ratio and natural oscillation angular frequency.

[0076] To verify the effectiveness of the present invention, a step input was added to the transfer function, and the actual step response was compared with the theoretically calculated value. Some parameter values ​​are shown in Table 1:

[0077]

[0078] Table 1

[0079] First, calculations are performed based on the line parameters. k p =3.33, and determine oh B =100π, add a damping element ， The active power-frequency transfer function for matched control can then be obtained as (11):

[0080] (11)

[0081] If an active response is required, the natural oscillation angular frequency... oh n At 5-10 rad / s, the damping ratio g Within the range of 0.3-1, according to the flowchart, the following can be calculated:

[0082] K c The range is 0.006877~0.0275. K δ The range is 9.4255~251.27, which means the parameter tuning is complete.

[0083] Selected oh n =5 rad / s, damping ratio g Taking 0.3 as an example, the following can be calculated: K c It is 0.006877. K δ The response curve obtained is 37.7, as shown below. Figure 4 As shown.

[0084] from Figure 4 The time difference between the two peaks is approximately 1.3 seconds, i.e., T ≈ 1.3 seconds. The theoretically calculated damped oscillation angular frequency... 4.7697 rad / s, then f d = =0.759Hz, T=1 / f d =1.317s, proving the correctness of the theoretical calculation.

[0085] If selected oh n The damping ratio is 5 rad / s. ζ 0.707 can then be calculated. K c It is 0.006877. K δ It is 88.8, such as Figure 5 As shown.

[0086] Similarly, theoretical calculations yield T=1.76, which is consistent with... Figure 5 The results corroborate each other.

[0087] Based on the same general inventive concept, this invention also protects an additional damping strategy and parameter tuning device for a matched control grid converter. The additional damping strategy and parameter tuning device for a matched control grid converter described below can be referred to in correspondence with the additional damping strategy and parameter tuning method for a matched control grid converter described above.

[0088] Figure 6 This is a schematic diagram of the structure of the additional damping strategy and parameter tuning device for the grid converter based on matched control provided in this embodiment.

[0089] like Figure 6 As shown, this embodiment provides an additional damping strategy and parameter tuning device for a matched control type grid converter, including:

[0090] The determining module 601 is used to determine circuit parameters, including: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit for the additional damping stage; determining the circuit parameters of the matching control circuit for the additional damping stage based on the power angle relationship of the grid-side converter output, including: the output voltage amplitude of the grid-side converter, the voltage amplitude of the grid connection point, and the line impedance between the two points; calculating the power angle coefficient and the frequency base value through the circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; and using the ratio of the product to the line impedance between the two points as the power angle coefficient.

[0091] The construction module 602 is used to construct an active-frequency response model for matched control with added damping based on the power angle coefficient and the frequency base value, including: determining the power relationship at both ends of the DC bus; combining the power relationship, the power angle coefficient, and the frequency base value to determine the angular frequency of the grid connection point, the grid-side converter, and the initial voltage phase of the grid connection point; inputting the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point into the transfer function model to obtain the active-frequency response model for matched control with added damping.

[0092] Solver module 603 is used to solve the damping ratio expression and the natural oscillation frequency expression using the active-frequency response model, including: obtaining the damping ratio expression and the natural oscillation frequency expression based on the active-frequency response model and the characteristics of the second-order transfer function;

[0093] The tuning module 604 is used to determine the control parameters in the active-frequency response model based on preset constraints, using the damping ratio expression and the natural oscillation frequency expression; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active-frequency response model includes:

[0094] ;

[0095] in, K c This represents the DC voltage matching factor. K δThis represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0096] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this embodiment.

[0097] like Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other through the communication bus 740. The processor 710 can call logic instructions in the memory 730 to execute a matching control-based grid converter additional damping strategy and parameter tuning method. This method includes: determining circuit parameters, including adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit for the additional damping stage; determining the circuit parameters of the matching control circuit for the additional damping stage based on the power angle relationship of the grid-side converter output, including the grid-side converter output voltage amplitude, the grid connection point voltage amplitude, and the line impedance between the two points; calculating the power angle coefficient and frequency base value through the circuit parameters, including determining the product of the grid-side converter output voltage amplitude and the grid connection point voltage amplitude; using the ratio of the product to the line impedance between the two points as the power angle coefficient; and constructing an active power-frequency response model for the damped matching control based on the power angle coefficient and the frequency base value, including determining the power relationship at both ends of the DC bus. Combining the power relationship, the power angle coefficient, and the frequency base value, determine the angular frequency of the grid connection point, the grid-side converter, and the initial voltage phase of the grid connection point; input the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point into the transfer function model to obtain the active power-frequency response model with added damping control; using the active power-frequency response model, solve for the damping ratio expression and the natural oscillation frequency expression, including: obtaining the damping ratio expression and the natural oscillation frequency expression based on the active power-frequency response model and the characteristics of the second-order transfer function; based on preset constraints, using the damping ratio expression and the natural oscillation frequency expression, determine the control parameters in the active power-frequency response model; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active power-frequency response model includes:

[0098] ;

[0099] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0100] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0101] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the above-described methods for the additional damping strategy and parameter tuning method of a matched control type grid converter. The method includes:

[0102] The circuit parameters are determined, including: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit with an additional damping element; determining the circuit parameters of the matching control circuit with the additional damping element based on the power angle relationship of the grid-side converter output, including: the output voltage amplitude of the grid-side converter, the voltage amplitude of the grid connection point, and the line impedance between the two points; calculating the power angle coefficient and the frequency base value through the circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; using the ratio of the product to the line impedance between the two points as the power angle coefficient; constructing an active power-frequency response model for the damped matching control based on the power angle coefficient and the frequency base value, including: determining the power relationship at both ends of the DC bus; and determining the grid connection by combining the power relationship, the power angle coefficient, and the frequency base value. The angular frequency of the point, the initial voltage phase of the grid-side converter and the grid connection point; input the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point to the transfer function model to obtain the active power-frequency response model with added damping element matching control; using the active power-frequency response model, solve for the damping ratio expression and the natural oscillation frequency expression, including: based on the active power-frequency response model and the characteristics of the second-order transfer function, obtain the damping ratio expression and the natural oscillation frequency expression; based on preset constraints, use the damping ratio expression and the natural oscillation frequency expression to determine the control parameters in the active power-frequency response model; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active power-frequency response model includes:

[0103] ;

[0104] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0105] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described methods for performing the additional damping strategy and parameter tuning method for matched control grid converters, the method comprising:

[0106] The circuit parameters are determined, including: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit with an additional damping element; determining the circuit parameters of the matching control circuit with the additional damping element based on the power angle relationship of the grid-side converter output, including: the output voltage amplitude of the grid-side converter, the voltage amplitude of the grid connection point, and the line impedance between the two points; calculating the power angle coefficient and the frequency base value through the circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; using the ratio of the product to the line impedance between the two points as the power angle coefficient; constructing an active power-frequency response model for the damped matching control based on the power angle coefficient and the frequency base value, including: determining the power relationship at both ends of the DC bus; and determining the grid connection by combining the power relationship, the power angle coefficient, and the frequency base value. The angular frequency of the point, the initial voltage phase of the grid-side converter and the grid connection point; input the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, and the initial voltage phase of the grid-side converter and the grid connection point to the transfer function model to obtain the active power-frequency response model with added damping element matching control; using the active power-frequency response model, solve for the damping ratio expression and the natural oscillation frequency expression, including: based on the active power-frequency response model and the characteristics of the second-order transfer function, obtain the damping ratio expression and the natural oscillation frequency expression; based on preset constraints, use the damping ratio expression and the natural oscillation frequency expression to determine the control parameters in the active power-frequency response model; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active power-frequency response model includes:

[0107] ;

[0108] in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. oh n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. oh B Indicates the base frequency value. g This indicates the damping ratio.

[0109] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0110] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A damping strategy and parameter tuning method for a matched-control grid converter, characterized in that, include: Determining circuit parameters includes: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit with an additional damping element. ； in, and Output phase angle of grid-side converter The two components, K δ The damping coefficient is... ω B Indicates the base frequency value. ω It is the actual output angular frequency of the converter, and s represents the Laplace operator; Based on the power angle relationship of the grid-side converter output, the circuit parameters of the matching control circuit of the additional damping element are determined, including: the output voltage amplitude of the grid-side converter, the voltage amplitude of the grid connection point, and the line impedance between the two points. The calculation of the power angle coefficient and frequency base value using the circuit parameters includes: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude of the grid connection point; and using the ratio of the product to the line impedance between the two points as the power angle coefficient. Based on the power angle coefficient and the frequency base value, an active-frequency response model for matched control with damping is constructed: ； in, k p Indicates the power angle coefficient. ω B Indicates the base frequency value. K c This represents the DC voltage matching factor. K δ represents the damping coefficient, s represents the Laplace operator, and C represents the DC capacitance; Using the active-frequency response model, solve for the damping ratio expression and the natural oscillation frequency expression; Based on preset constraints, the control parameters in the active-frequency response model are determined using the damping ratio expression and the natural oscillation frequency expression. The control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active-frequency response model includes: ； in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. ω n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. ω B Indicates the base frequency value. ζ This indicates the damping ratio.

2. The additional damping strategy and parameter tuning method for a grid-connected converter based on matched control as described in claim 1, characterized in that, The active-frequency response model for matched control with damping is constructed based on the power angle coefficient and the frequency base value, including: Determine the power relationship at both ends of the DC bus; Combining the power relationship, the power angle coefficient, and the frequency base value, the active-frequency response model of the matched control with added damping is obtained using the small-signal analysis method.

3. The additional damping strategy and parameter tuning method for a grid-connected converter based on matched control as described in claim 2, characterized in that, The active-frequency response model of the matched control with added damping element obtained by using the small-signal analysis method includes: Determine the angular frequency of the grid connection point, the grid-side converter, and the initial voltage phase of the grid connection point; By inputting the power angle coefficient, the frequency base value, the angular frequency of the grid connection point, the initial voltage phase of the grid-side converter and the grid connection point into the transfer function model, the active power-frequency response model of the matched control with the addition of an additional damping element is obtained.

4. The additional damping strategy and parameter tuning method for a grid-connected converter based on matched control as described in claim 1, characterized in that, The process of using the active-frequency response model to solve for the damping ratio expression and the natural oscillation frequency expression includes: Based on the active-frequency response model and the characteristics of the second-order transfer function, the expressions for the damping ratio and the natural oscillation frequency are obtained.

5. A damping strategy and parameter tuning device for a matched-control grid converter, characterized in that, include: The determination module is used to determine circuit parameters, including: adding a proportional element to the phase angle generation stage of the circuit to obtain a matching control circuit with an additional damping element. ； in, and Output phase angle of grid-side converter The two components, K δ The damping coefficient is... ω B Indicates the base frequency value. ω Here, ω is the actual output angular frequency of the converter, and s represents the Laplace operator. Based on the power angle relationship of the grid-side converter output, the circuit parameters of the matching control circuit of the additional damping element are determined, including: the output voltage amplitude of the grid-side converter, the voltage amplitude at the grid connection point, and the line impedance between the two points. The power angle coefficient and frequency base value are calculated through the circuit parameters, including: determining the product of the output voltage amplitude of the grid-side converter and the voltage amplitude at the grid connection point; and using the ratio of the product to the line impedance between the two points as the power angle coefficient. The module is used to construct an active-frequency response model for matched control with damping, based on the power angle coefficient and the frequency base value. ； in, k p Indicates the power angle coefficient. ω B Indicates the base frequency value. K c This represents the DC voltage matching factor. K δ represents the damping coefficient, s represents the Laplace operator, and C represents the DC capacitance; The solution module is used to solve the damping ratio expression and the natural oscillation frequency expression using the active-frequency response model, including: obtaining the damping ratio expression and the natural oscillation frequency expression based on the active-frequency response model and the characteristics of the second-order transfer function; The tuning module is used to determine the control parameters in the active-frequency response model based on preset constraints, using the damping ratio expression and the natural oscillation frequency expression; the control parameters include: DC voltage matching coefficient and damping coefficient; determining the control parameters in the active-frequency response model includes: ； in, K c This represents the DC voltage matching factor. K δ This represents the damping coefficient, and C represents the DC capacitance. ω n Indicates the natural oscillation angular frequency. k p Indicates the power angle coefficient. ω B Indicates the base frequency value. ζ This indicates the damping ratio.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the additional damping strategy and parameter tuning method for a grid converter based on matched control as described in any one of claims 1-4.

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