Grid-type converter matching control method and system

Abstract

The present invention provides a grid-type converter matching control method and system, which belongs to the technical field of converter matching control. The phase is calculated by combining the target reference value of the converter DC side voltage, the target reference value of the AC grid frequency and the actual value of the converter DC side voltage; the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point are calculated according to the three-phase voltage and the three-phase current, and the actual modulation signal amplitude is obtained by combining the line voltage amplitude of the AC grid; the modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and the grid-type converter matching control is performed according to the modulation wave signal and the DC current. Compared with the traditional droop control and VSM control, the matching control of the present invention is more stable in a hybrid grid where a synchronous machine and an inverter coexist; no phase-locked loop is required to extract the phase, and the synchronous machine rotor angular velocity is matched with the DC voltage to simulate synchronization and obtain the angular velocity and phase.

Description

Technical Field

[0001] The present invention relates to the technical field of converter matching control, and in particular to a grid-type converter matching control method and system with active frequency support capability. Background Art

[0002] With the development of renewable energy, the traditional grid mode has changed. Renewable energy is usually connected to the AC grid through an inverter. The power system has gradually formed a hybrid grid where inverters and synchronous machine interfaces coexist, especially in some microgrids. This situation may cause many problems, mostly caused by the response time difference between the synchronous machine and the inverter. Traditional droop control is widely used in inverters, but it cannot provide inertia, which will result in a faster response time for the inverter. Summary of the invention

[0003] The purpose of the present invention is to provide a grid-type converter matching control method and system with active frequency support capability, which has the characteristics of more stable matching control in a hybrid power grid where synchronous machines and inverters coexist, and the characteristics of power frequency droop control and frequency support, so as to solve at least one technical problem existing in the above background technology.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a grid-type converter matching control method, comprising:

[0006] Collect the actual voltage value of the DC side of the converter;

[0007] Calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency, and an actual value of the DC side voltage of the converter;

[0008] Collect three-phase voltage and three-phase current at the grid-connected point of the converter;

[0009] Calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point based on the collected three-phase voltage and three-phase current;

[0010] According to the target reference value of the effective value of the three-phase voltage at the grid-connected point of the converter and the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid, the actual modulation signal amplitude is obtained;

[0011] A modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and matching control of the grid-forming converter is performed according to the modulation wave signal and the direct current.

[0012] Furthermore, based on the target reference value of the DC side voltage of the converter and the target reference value of the AC grid frequency, the target reference value of the simulated synchronous motor rotor angular velocity and the coefficient of the matching control inner loop are calculated; the actual value of the DC side voltage of the converter is multiplied by the coefficient of the matching control inner loop to obtain the simulated synchronous motor rotor angular velocity; and the angular velocity is integrated to obtain the phase.

[0013] Furthermore, the difference between the target reference value of the effective value of the phase voltage at the grid-connected point of the converter and the effective value of the three-phase voltage at the grid-connected point of the converter is calculated, and the difference is input into the PI control module to obtain the amplitude deviation compensation amount of the modulation signal.

[0014] Furthermore, according to the line voltage amplitude of the AC power grid, a target reference value of the effective value of the line voltage is calculated to obtain a target modulation signal amplitude; the actual modulation signal amplitude is obtained by summing the target modulation signal amplitude and the amplitude deviation compensation amount.

[0015] Furthermore, the amplitude deviation compensation amount Δμ of the modulation signal is obtained, and the calculation formula is as follows:

[0016]

[0017] Among them, K P_μ is the proportional control parameter; K I_μ is the integral control parameter; s is the complex variable in Laplace transform.

[0018] Furthermore, the modulated wave signal is obtained from the phase θ and the modulation signal amplitude μ:

[0019]

[0020] Furthermore, the target reference value of the active power input at the grid-connected point of the converter is set as P PCCref , calculate P PCCref The difference between the active power input at the inverter grid connection point and the active power droop coefficient K is then multiplied to obtain the DC voltage amplitude deviation compensation ΔV dc , ΔV dc Add the target reference value of the DC side voltage of the converter and subtract the actual value of the DC side voltage of the converter V dc Input into the PI control module to obtain the DC current amplitude deviation compensation ΔI s .

[0021] Further, the target reference value of the DC current I is obtained by dividing the target reference value of the active power input at the grid-connected point of the converter by the target reference value of the DC side voltage of the converter. sref , I sref The DC current is obtained by adding the DC current amplitude deviation compensation.

[0022] Furthermore, the DC current amplitude deviation compensation ΔI s , the calculation formula is as follows:

[0023]

[0024] Among them, K P_Is is the proportional control parameter; K I_Is is the integral control parameter; s is the complex variable in Laplace transform.

[0025] In a second aspect, the present invention provides a grid-type converter matching control system, comprising:

[0026] The first acquisition module is used to acquire the actual value of the voltage on the DC side of the converter;

[0027] A first calculation module is used to calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency and an actual value of the DC side voltage of the converter;

[0028] The second acquisition module is used to collect the three-phase voltage and three-phase current at the grid connection point of the converter;

[0029] The second calculation module is used to calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point according to the collected three-phase voltage and three-phase current;

[0030] The third calculation module is used to obtain the actual modulation signal amplitude according to the effective value of the three-phase voltage at the grid-connected point of the converter and the target reference value of the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid;

[0031] The control module is used to obtain a modulation wave signal according to the phase and the actual modulation signal amplitude, and to perform matching control of the grid-forming converter according to the modulation wave signal and the DC current.

[0032] In a third aspect, the present invention provides a non-transitory computer-readable storage medium, which is used to store computer instructions. When the computer instructions are executed by a processor, the grid-type converter matching control method with active frequency support capability as described in the first aspect is implemented.

[0033] In a fourth aspect, the present invention provides a computer device comprising a memory and a processor, wherein the processor and the memory communicate with each other, the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the grid-type converter matching control method with active frequency support capability as described in the first aspect.

[0034] In a fifth aspect, the present invention provides an electronic device, comprising: a processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory so that the electronic device executes instructions for implementing the method for matching and controlling a grid-connected converter with active frequency support capability as described in the first aspect.

[0035] Beneficial effects of the present invention: Compared with traditional droop control and VSM control, matching control is more stable in a hybrid power grid where synchronous machines and inverters coexist; no phase-locked loop is required to extract the phase, and synchronization is simulated and the angular velocity and phase are obtained by matching the synchronous machine rotor angular velocity with a DC voltage.

[0036] Additional advantages of the present invention will be more clearly given in the following description or learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0038] Figure 1 This is a topology diagram of a converter with three-phase voltage support according to an embodiment of the present invention.

[0039] Figure 2 This is a flow chart of inner loop matching control according to an embodiment of the present invention.

[0040] Figure 3 This is a flow chart of outer loop active power droop and VF control according to an embodiment of the present invention.

[0041] Figure 4 Schematic diagram of a DC voltage variation curve according to an embodiment of the present invention.

[0042] Figure 5 The figure is a schematic diagram of a curve showing a change in the effective value of the three-phase voltage on the AC side according to an embodiment of the present invention.

[0043] Figure 6 It is a schematic diagram of a curve of active power variation input at a grid-connected point of a converter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below by the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0045] It should be understood by those skilled in the art that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0046] It should also be understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with that in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless as defined herein.

[0047] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements and / or groups thereof.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. Different embodiments or examples described in this specification and features of different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

[0049] To facilitate understanding of the present invention, the present invention is further explained below with reference to specific embodiments in conjunction with the accompanying drawings, and the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0050] Those skilled in the art should understand that the drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

[0051] Example 1

[0052] In this embodiment 1, a grid-type converter matching control system is first provided, including: a first acquisition module, used to acquire the actual value of the voltage on the DC side of the converter; a first calculation module, used to calculate the phase by combining the target reference value of the DC side voltage of the converter, the target reference value of the AC power grid frequency and the actual value of the voltage on the DC side of the converter; a second acquisition module, used to acquire the three-phase voltage and three-phase current at the grid-connected point of the converter; a second calculation module, used to calculate the active power input at the grid-connected point of the converter and the effective value of the three-phase voltage at the grid-connected point of the converter based on the acquired three-phase voltage and three-phase current; a third calculation module, used to obtain the actual modulation signal amplitude based on the effective value of the three-phase voltage at the grid-connected point of the converter and the target reference value of the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid; a control module, used to obtain the modulation wave signal according to the phase and the actual modulation signal amplitude, and perform grid-type converter matching control according to the modulation wave signal and the DC current.

[0053] In this embodiment, based on the above-mentioned grid-type converter matching control system, a grid-type converter matching control method is implemented, including: collecting the actual value of the voltage on the DC side of the converter; calculating the phase in combination with the target reference value of the DC side voltage of the converter, the target reference value of the AC power grid frequency and the actual value of the voltage on the DC side of the converter; collecting the three-phase voltage and three-phase current at the converter grid-connected point; calculating the active power input at the converter grid-connected point and the effective value of the three-phase voltage at the converter grid-connected point based on the collected three-phase voltage and three-phase current; obtaining the actual modulation signal amplitude based on the effective value of the three-phase voltage at the converter grid-connected point and the target reference value of the effective value of the phase voltage at the converter grid-connected point, combined with the line voltage amplitude of the AC power grid; obtaining the modulation wave signal based on the phase and the actual modulation signal amplitude, and performing grid-type converter matching control based on the modulation wave signal and the DC current.

[0054] Among them, according to the target reference value of the DC side voltage of the converter and the target reference value of the AC grid frequency, the target reference value of the simulated synchronous motor rotor angular velocity and the coefficient of the matching control inner loop are calculated; the actual value of the voltage on the DC side of the converter is multiplied by the coefficient of the matching control inner loop to obtain the simulated synchronous motor rotor angular velocity; the angular velocity is integrated to obtain the phase. The difference between the target reference value of the effective value of the phase voltage at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point is calculated, and the difference is input into the PI control module to obtain the amplitude deviation compensation of the modulation signal. According to the line voltage amplitude of the AC grid, the target reference value of the effective value of the line voltage is calculated to obtain the target modulation signal amplitude; the sum of the target modulation signal amplitude and the amplitude deviation compensation amount obtains the actual modulation signal amplitude.

[0055] The amplitude deviation compensation Δμ of the modulation signal is obtained, and the calculation formula is as follows:

[0056]

[0057] Among them, K P_μ is the proportional control parameter; K I_μ is the integral control parameter; s is the complex variable in Laplace transform.

[0058] The modulated wave signal obtained by the phase θ and the modulation signal amplitude μ is:

[0059] Set the target reference value of the active power input at the inverter grid connection point to P PCCref , calculate P PCCref The difference between the active power input at the inverter grid connection point and the active power droop coefficient K is then multiplied to obtain the DC voltage amplitude deviation compensation ΔV dc , ΔV dc Add the target reference value of the DC side voltage of the converter and subtract the actual value of the DC side voltage of the converter V dc Input into the PI control module to obtain the DC current amplitude deviation compensation ΔI s The target reference value of the DC current I is obtained by dividing the target reference value of the active power input at the grid-connected point of the converter by the target reference value of the DC side voltage of the converter. sref , I sref The DC current is obtained by adding the DC current amplitude deviation compensation.

[0060] DC current amplitude deviation compensation ΔI s , the calculation formula is as follows:

[0061]

[0062] Among them, K P_Is is the proportional control parameter; K I_Is is the integral control parameter; s is the complex variable in Laplace transform.

[0063] Example 2

[0064] In this embodiment 2, a matching control method for a grid-connected converter with active frequency support capability is provided, which has both the characteristic of more stable matching control in a hybrid power grid where synchronous machines and inverters coexist, and the power frequency droop characteristic and frequency support characteristic of droop control.

[0065] In this embodiment, a grid-forming converter matching control method with active frequency support capability includes: constructing a current source type DC side and AC power grid model through a converter; constructing a grid-forming control strategy with active frequency support capability, specifically including the following steps:

[0066] (1) Set the target reference value V of the DC side voltage of the converter dcref, collect the actual voltage value Vdc on the DC side of the converter;

[0067] (2) Setting the target reference value f of the AC grid frequency ref According to the domestic frequency standard, let f ref =50Hz, and the target reference value ω of the simulated synchronous motor rotor angular velocity is obtained. ref , we can get the V matching the inner loop dc The -ω coefficient η is:

[0068]

[0069] (3) Collect the three-phase voltage V at the inverter grid connection point C , three-phase current i abc ;

[0070] (4) Calculate the active power P input at the transformer grid connection point based on the three-phase voltage and three-phase current collected in step (3) PCC And the three-phase voltage effective value at the inverter grid connection point||V C ||;

[0071] (5) Set the target reference value of the effective phase voltage at the grid connection point of the converter || V C || ref , calculate ||V C || ref Compared with ||V obtained in step (4) C The difference between ||Δ||V C ||, Δ||V C || Input into the PI control module to obtain the amplitude deviation compensation Δμ of the modulation signal. The calculation formula is as follows:

[0072]

[0073] Where: K P_μ is the proportional control parameter; K I_μ is the integral control parameter; s is the complex variable in Laplace transform;

[0074] (6) According to the line voltage amplitude V of the AC power grid CL , calculate the target reference value of the effective value of the line voltage || V CL || ref , set the amplitude μ of the target modulation signal ref for:

[0075]

[0076] (7) Δμ obtained from step (5) plus μ obtained from step (6) ref Get the modulation signal amplitude μ;

[0077] (8) Set the target reference value of the active power input at the inverter grid connection point as P PCCref , calculate P PCCref and P obtained in step (4) PCC The difference between them is multiplied by the active droop coefficient K to obtain the DC voltage amplitude deviation compensation ΔV dc , ΔV dc Add V dcref Subtract V dc Input into the PI control module to obtain the DC current amplitude deviation compensation ΔI s , the calculation formula is as follows:

[0078]

[0079] Where: K P_Is is the proportional control parameter; K I_Is is the integral control parameter; s is the complex variable in Laplace transform;

[0080] (9) P set by step (8) PCCref Divide by the V set in step (1) dcref Get the target reference value I of DC current sref , I sref Add the ΔI obtained in step (8) s Get the DC current I s ;

[0081] (10) V collected in step (1) dc Multiply by η obtained in step (2) to obtain the simulated synchronous motor rotor angular velocity ω;

[0082] (11) Integrating the angular velocity ω gives the phase θ;

[0083] (12) The modulated wave signal can be obtained from the phase θ and the modulation signal amplitude μ. The calculation formula is as follows:

[0084]

[0085] In the specific application of the grid-connected converter matching control method with active frequency support capability, when the grid frequency is normally 50 Hz, V dc V dcref Due to the existence of the η coefficient, the converter has the frequency support capability and can track f ref ; At this time P PCC It can also achieve P PCCref Tracking; AC side three-phase voltage effective value || V C ||Can also track||V C ||ref ; When the grid frequency fluctuates and changes to f, Vdc tracks f in proportion to the η coefficient. At this time, P PCC Presenting active frequency droop characteristics:

[0086]

[0087] V dcref -V dc -K(P PCC -P PCCref )=0

[0088]

[0089] Among them, the grid frequency fluctuation cannot exceed ±0.2Hz.

[0090] The system topology diagram of the grid-type converter matching control method with active frequency support capability is as follows: Figure 1 As shown, Figure 2 The matching control inner loop control strategy (i.e., steps (10) to (12)) shown in FIG. 1 and the active power droop and VF outer loop control strategies shown in (8)-(9) and (5) are shown in FIG. Figure 3 shown.

[0091] After building the relevant model in Matlab, simulation verification was carried out. The specific parameters are shown in Table 1.

[0092] When the grid frequency is stable at 50Hz, set P PCCref From 100MW to 110MW in the third second, the simulation results are: DC voltage V dc After reaching steady state, it is 200kV and can accurately track V dcref , and P PCCref After the change, it can quickly return to V dcref ,like Figure 4 As shown. AC side three-phase voltage effective value || V C ||Can also track||V C || ref ,like Figure 5 As shown; P PCC Can accurately follow P PCCref ,like Figure 6 shown.

[0093] Table 1

[0094]

[0095] Example 3

[0096] This embodiment 3 provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by a processor, the above-mentioned grid-connected converter matching control method with active frequency support capability is implemented. The method includes:

[0097] Collect the actual voltage value of the DC side of the converter;

[0098] Calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency, and an actual value of the DC side voltage of the converter;

[0099] Collect three-phase voltage and three-phase current at the grid-connected point of the converter;

[0100] Calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point based on the collected three-phase voltage and three-phase current;

[0101] According to the target reference value of the effective value of the three-phase voltage at the grid-connected point of the converter and the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid, the actual modulation signal amplitude is obtained;

[0102] A modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and matching control of the grid-forming converter is performed according to the modulation wave signal and the direct current.

[0103] Example 4

[0104] This embodiment 4 provides a computer device, including a memory and a processor, the processor and the memory communicate with each other, the memory stores program instructions executable by the processor, the processor calls the program instructions to execute the above-mentioned grid-connected converter matching control method with active frequency support capability, the method comprising:

[0105] Collect the actual voltage value of the DC side of the converter;

[0106] Calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency, and an actual value of the DC side voltage of the converter;

[0107] Collect three-phase voltage and three-phase current at the grid-connected point of the converter;

[0108] Calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point based on the collected three-phase voltage and three-phase current;

[0109] According to the target reference value of the effective value of the three-phase voltage at the grid-connected point of the converter and the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid, the actual modulation signal amplitude is obtained;

[0110] A modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and matching control of the grid-forming converter is performed according to the modulation wave signal and the direct current.

[0111] Example 5

[0112] This embodiment 5 provides an electronic device, including: a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes instructions for implementing the above-mentioned grid-connected converter matching control method with active frequency support capability, the method comprising:

[0113] Collect the actual voltage value of the DC side of the converter;

[0114] Calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency, and an actual value of the DC side voltage of the converter;

[0115] Collect three-phase voltage and three-phase current at the grid-connected point of the converter;

[0116] Calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point based on the collected three-phase voltage and three-phase current;

[0117] According to the target reference value of the effective value of the three-phase voltage at the grid-connected point of the converter and the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid, the actual modulation signal amplitude is obtained;

[0118] A modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and matching control of the grid-forming converter is performed according to the modulation wave signal and the direct current.

[0119] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0120] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0121] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device, and a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0123] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative work on the basis of the technical solution disclosed in the present invention should be included in the scope of protection of the present invention.

Claims

1. A grid-type converter matching control method, characterized in that: include: Collect the actual voltage value of the DC side of the converter; Calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency, and an actual value of the DC side voltage of the converter; Collect three-phase voltage and three-phase current at the grid-connected point of the converter; Calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point based on the collected three-phase voltage and three-phase current; According to the target reference value of the effective value of the three-phase voltage at the grid-connected point of the converter and the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid, the actual modulation signal amplitude is obtained; A modulation wave signal is obtained according to the phase and the actual modulation signal amplitude, and matching control of the grid-type converter is performed according to the modulation wave signal and the DC current; in, According to the target reference value of the DC side voltage of the converter and the target reference value of the AC power grid frequency, the target reference value of the simulated synchronous motor rotor angular velocity and the coefficient of the matching control inner loop are calculated; the actual value of the DC side voltage of the converter is multiplied by the coefficient of the matching control inner loop to obtain the simulated synchronous motor rotor angular velocity; the angular velocity is integrated to obtain the phase; the difference between the target reference value of the effective value of the phase voltage at the converter grid-connected point and the effective value of the three-phase voltage at the converter grid-connected point is calculated, and the difference is input into the PI control module to obtain the amplitude deviation compensation of the modulation signal; according to the line voltage amplitude of the AC power grid, the target reference value of the effective value of the line voltage is calculated to obtain the target modulation signal amplitude; the sum of the target modulation signal amplitude and the amplitude deviation compensation amount obtains the actual modulation signal amplitude.

2. The grid-type converter matching control method according to claim 1, characterized in that: The amplitude deviation compensation Δμ of the modulation signal is obtained, and the calculation formula is as follows: Among them, K P_μ is the proportional control parameter; K I_μ is the integral control parameter; s is the complex variable in Laplace transform; ||V C || represents the effective value of the three-phase voltage at the grid-connected point of the converter; || V C || ref It represents the target reference value of the effective value of the phase voltage at the grid-connected point of the converter.

3. The grid-type converter matching control method according to claim 1, characterized in that: The modulated wave signal obtained by the phase θ and the modulation signal amplitude μ is:

4. The grid-type converter matching control method according to claim 1, characterized in that: Set the target reference value of the active power input at the inverter grid connection point to P PCCref , calculate P PCCref The difference between the active power input at the inverter grid connection point and the active power droop coefficient K is then multiplied to obtain the DC voltage amplitude deviation compensation ΔV dc , ΔV dc Add the target reference value of the DC side voltage of the converter and subtract the actual value of the DC side voltage of the converter V dc Input into the PI control module to obtain the DC current amplitude deviation compensation ΔI s .

5. The grid-type converter matching control method according to claim 4, characterized in that: The target reference value of the DC current I is obtained by dividing the target reference value of the active power input at the grid connection point of the converter by the target reference value of the DC side voltage of the converter. sref , I sref The DC current is obtained by adding the DC current amplitude deviation compensation.

6. The grid-type converter matching control method according to claim 5, characterized in that: DC current amplitude deviation compensation ΔI s , the calculation formula is as follows: Among them, K P_Is is the proportional control parameter; K I_Is is the integral control parameter; s is the complex variable in Laplace transform; V dcref Indicates the target reference value of the converter DC side voltage.

7. A grid-type converter matching control system, characterized in that: include: The first acquisition module is used to acquire the actual value of the voltage on the DC side of the converter; A first calculation module is used to calculate the phase by combining a target reference value of the DC side voltage of the converter, a target reference value of the AC grid frequency and an actual value of the DC side voltage of the converter; The second acquisition module is used to collect the three-phase voltage and three-phase current at the grid connection point of the converter; The second calculation module is used to calculate the active power input at the converter grid connection point and the effective value of the three-phase voltage at the converter grid connection point according to the collected three-phase voltage and three-phase current; The third calculation module is used to obtain the actual modulation signal amplitude according to the effective value of the three-phase voltage at the grid-connected point of the converter and the target reference value of the effective value of the phase voltage at the grid-connected point of the converter, combined with the line voltage amplitude of the AC power grid; A control module, used to obtain a modulation wave signal according to the phase and the actual modulation signal amplitude, and to perform matching control of the grid-forming converter according to the modulation wave signal and the DC current; in, According to the target reference value of the DC side voltage of the converter and the target reference value of the AC power grid frequency, the target reference value of the simulated synchronous motor rotor angular velocity and the coefficient of the matching control inner loop are calculated; the actual value of the DC side voltage of the converter is multiplied by the coefficient of the matching control inner loop to obtain the simulated synchronous motor rotor angular velocity; the angular velocity is integrated to obtain the phase; the difference between the target reference value of the effective value of the phase voltage at the converter grid-connected point and the effective value of the three-phase voltage at the converter grid-connected point is calculated, and the difference is input into the PI control module to obtain the amplitude deviation compensation of the modulation signal; according to the line voltage amplitude of the AC power grid, the target reference value of the effective value of the line voltage is calculated to obtain the target modulation signal amplitude; the sum of the target modulation signal amplitude and the amplitude deviation compensation amount obtains the actual modulation signal amplitude.

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