Hybrid amplitude control method and system based on network-forming converter

Abstract

The invention relates to the technical field of converter control, in particular to a mixed amplitude control method and system based on a network-forming converter, in a power grid system, firstly, the output current and three-phase voltage of the input side of a three-phase converter are obtained, and the power is calculated according to the output current and the three-phase voltage to obtain first power; p-omega droop control is implemented based on the first power to obtain a first frequency signal, and the first frequency signal is converted into a first control signal after integration. Thirdly, three-phase current and three-phase voltage output by the three-phase converter are converted into a dq coordinate system, mixed amplitude control is carried out on the voltage and the current in the coordinate system, and a second control signal used for adjusting the amplitude of the voltage and the amplitude of the current is generated; and finally, synthesizing the first control signal and the second control signal to obtain a modulated wave signal, thereby realizing feedback control of the three-phase converter.

Description

Technical Field

[0001] The present invention relates to the technical field of converter control, and particularly relates to a hybrid amplitude control method and system based on a grid-forming converter. Background Art

[0002] Grid-forming inverters (GFMs) are widely used in actual engineering. Grid-forming inverters can actively regulate the grid voltage and frequency, so they perform well under islanding operation and weak grid conditions.

[0003] Under islanding operation and weak grid conditions, the ability of grid-forming inverters to actively regulate the grid voltage and frequency is particularly crucial. A grid-forming inverter (GFM) can achieve grid synchronization by means of active power - frequency droop control (i.e., P-ω droop control) or DC-side voltage synchronization control. Essentially, it is equivalent to a controlled voltage source. With its active voltage and frequency support capabilities, grid-forming inverters have shown significant advantages in improving grid stability, adapting to high-proportion new energy access, and enhancing the operation ability of microgrids. Given the accelerating global energy transition and the rapid development of smart grids and microgrids, grid-forming inverters are bound to play a crucial role in future power systems, and their development prospects are extremely broad.

[0004] However, when a GFM converter is connected to a strong grid, due to the difference in synchronization between its own control strategy and the external grid, especially in the case of high grid connection strength, unstable conditions may occur. Therefore, how to improve the instability of grid-forming converters in a strong grid environment has become an important research direction in the field of modern power systems. Currently, there are various ways to improve the stability of GFM converters in a strong grid environment. For example, virtual synchronous machines and virtual inertia enhancement systems are used to enhance the regulation ability of the grid frequency and voltage; hierarchical control and adaptive control are adopted to avoid over-regulation, thereby improving the flexibility and robustness of the system; through non-linear control and optimization algorithms, dynamic optimization regulation of the system is achieved, etc.

[0005] The so-called hybrid control refers to the integration of two or more control strategies in the process of power system or inverter control, aiming to give full play to the advantages of each control method, thereby improving the stability, efficiency, and adaptability of the system. In modern power systems, especially in new energy (such as wind power, solar energy, etc.) and distributed energy systems, hybrid control is widely used to solve complex control problems, strongly promoting the development of power systems towards intelligence and flexibility. However, currently, existing hybrid control methods basically belong to hybrid synchronous control, lacking the hybrid part of amplitude control. For grid-forming converters, methods for improving converter performance from the perspective of hybrid control are still relatively scarce. Summary of the Invention The technical problem to be solved by the present invention is to provide a hybrid amplitude control method and system based on a grid-forming converter in view of the deficiencies in the above-mentioned prior art, providing new ideas and methods for improving the performance of the system and adapting to complex operating conditions.

[0006] The object of the present invention is achieved by the following technical solutions: In a first aspect, the present invention provides a hybrid amplitude control method based on a grid-forming converter, including: Obtain the output current and three-phase voltage of the three-phase converter on the input side in the power grid system; Perform power calculation based on the output current and three-phase voltage of the three-phase converter to obtain a first power; Perform P-ω droop control based on the first power to obtain a first frequency signal, and integrate the first frequency signal to obtain a first control signal; Convert the output three-phase current and three-phase voltage of the three-phase converter to the dq coordinate system, perform hybrid amplitude control on the three-phase voltage and three-phase current in the dq coordinate system, and generate a second control signal for adjusting the amplitudes of the voltage and current; Obtain a modulation wave signal based on the first control signal and the second control signal, and perform feedback control of the three-phase converter according to the modulation wave signal.

[0007] As a further improvement of the present invention, performing P-ω droop control based on the first power to obtain a first frequency signal, and integrating the first frequency signal to obtain a first control signal, specifically includes: Use the first power to synchronously control the input-side inverter and the load in the power grid system, and control the response speed and power distribution by adjusting the droop coefficient; Obtain the output frequency of the input-side inverter as the first frequency, and integrate the first frequency through an integrator to obtain the first control signal required for the grid connection control of the converter.

[0008] As a further improvement of the present invention, in the P-ω droop control, the output frequency of the input-side inverter and the load power satisfy:

[0009] Wherein, is the output frequency of the input-side inverter, is the rated frequency of the power grid system, is the droop coefficient, is the output power of the input-side inverter.

[0010] As a further improvement of the present invention, the three-phase current and three-phase voltage output by the three-phase converter are converted into the dq coordinate system, and hybrid amplitude control is performed on the three-phase voltage and three-phase current in the dq coordinate system, specifically including: Obtain the rated reference value of the d-axis voltage and the rated reference value of the q-axis current; Convert the three-phase voltage output by the three-phase converter into the dq coordinate system to obtain the d-axis voltage component and the q-axis voltage component respectively. Perform GFM amplitude control according to the d-axis voltage component and the rated reference value of the d-axis voltage to obtain the rated reference value of the d-axis current; Convert the three-phase current output by the three-phase converter into the dq coordinate system to obtain the d-axis current component and the q-axis current component. Perform GFL amplitude control according to the d-axis current component, the rated reference value of the d-axis current, the q-axis current component and the rated reference value of the q-axis current to obtain the d-axis voltage control signal and the q-axis voltage control signal respectively; According to the d-axis voltage control signal, the q-axis voltage control signal and the first control signal, convert them into the abc coordinate system to obtain the second control signal.

[0011] As a further improvement of the present invention, the GFM amplitude control and GFL amplitude control respectively include: The GFM amplitude control includes: taking the d-axis voltage component of the output voltage of the three-phase converter and the rated reference value of the d-axis voltage as the input of the voltage outer loop; subtracting the d-axis voltage component from the rated reference value of the d-axis voltage, and after PI control of the obtained difference, obtaining the rated reference value of the d-axis current; The GFL amplitude control includes: taking the q-axis current component of the output current of the three-phase converter and the rated reference value of the q-axis current as the input of the current inner loop; subtracting the q-axis current component from the rated reference value of the q-axis current, and after PI control of the obtained difference, obtaining the q-axis control voltage signal; subtracting the d-axis current component from the rated reference value of the d-axis current output by the voltage outer loop, and after PI control of the obtained difference, obtaining the d-axis control voltage signal.

[0012] As a further improvement of the present invention, when calculating the power according to the output current and three-phase voltage of the three-phase converter, the three-phase voltage used is the voltage value after LCL filtering; the three-phase current used is the current value after LCL filtering.

[0013] As a further improvement of the present invention, after the second control signal passes through pulse width modulation, a modulation wave signal for driving the three-phase converter is obtained.

[0014] In a second aspect, the present invention provides a hybrid amplitude control system based on a grid-forming converter for implementing the above-mentioned hybrid amplitude control method based on a grid-forming converter, including: A power calculation module, configured to calculate power based on the output current and three-phase voltage of a three-phase converter to obtain a first power; A droop control module, configured to perform P-ω droop control based on the first power to obtain a first frequency signal, and integrate the first frequency signal to obtain a first control signal; A data acquisition module, configured to acquire the output current and three-phase voltage of the three-phase converter on the input side in the power grid system; A coordinate transformation module, configured to perform coordinate transformation on the output three-phase current and three-phase voltage of the three-phase converter to obtain the three-phase voltage and three-phase current in the dq coordinate system; A hybrid amplitude control module, configured to perform hybrid amplitude control on the three-phase voltage and three-phase current in the dq coordinate system to generate a second control signal for adjusting the amplitudes of the voltage and current; obtain a modulation wave signal based on the first control signal and the second control signal, and perform feedback control on the three-phase converter according to the modulation wave signal.

[0015] In a third aspect, the present invention provides a computer-readable storage medium storing one or more programs, where the one or more programs include instructions that, when executed by a computing device, cause the computing device to execute the above-mentioned hybrid amplitude control method based on a network-forming converter.

[0016] In a fourth aspect, the present invention provides a computing device, including: One or more processors, a memory, and one or more programs, where the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include steps for executing the above-mentioned hybrid amplitude control method based on a network-forming converter.

[0017] The beneficial effects of the present invention are as follows: The hybrid amplitude control method based on a network-forming converter provided by the present invention can automatically adjust the frequency according to the change of load power through P-ω droop control, thereby maintaining the stability of the system frequency. The precise control of voltage and current by the hybrid amplitude control further improves the stability of the system. The P-ω droop control can quickly respond to the change of load power, while the hybrid amplitude control provides the ability to quickly adjust voltage and current, ensuring that the dynamic response speed of the system is accelerated, and it can quickly adjust the output when the load changes, ensuring the power supply quality. At the same time, the P-ω droop control adjusts the frequency according to the power change, thereby realizing the reasonable distribution of power. The hybrid amplitude control ensures the precise control of voltage and current, avoiding power imbalance. This feedback control method realizes the precise control of the three-phase converter in the power grid system by combining P-ω droop control and hybrid amplitude control.

[0018] Furthermore, through P-ω droop control, the inverter can automatically adjust the output frequency according to the change of load power, achieve synchronization with the power grid, and thus ensure the stability and reliability of power supply. By adjusting the droop coefficient m, the response speed of the system can be controlled. A larger droop coefficient m can accelerate the response speed, while a smaller droop coefficient m can improve the stability of the system.

[0019] Furthermore, by converting the output of the three-phase converter to the dq coordinate system and performing hybrid amplitude control, this method achieves precise control of voltage and current. Hybrid amplitude control realizes the balance of active power and reactive power by adjusting the d-axis and q-axis voltages and currents. It improves the power factor of the system, reduces the consumption of reactive power, and optimizes energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is the circuit diagram and simplified control block diagram of the grid-forming converter grid-connected system applicable to the present invention.

[0022] Figure 2 It is the hybrid amplitude control block diagram of the d-axis voltage and q-axis current proposed by the present invention.

[0023] Figure 3 It is the simulation waveform diagram of the control method proposed by the present invention in the single-machine infinite grid-connected system.

[0024] Figure 4 is a comparison diagram of the hybrid amplitude control method proposed by the present invention and the traditional grid-forming double-loop control in the face of the infinite grid frequency change. Among them, Figure (a) is the waveform diagram of the traditional grid-forming double-closed-loop control when the grid strength changes, and Figure (b) is the waveform diagram of the control proposed by the present invention.

[0025] Figure 5 It is the structural schematic diagram of the electronic device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to make the purpose and technical solutions of the present invention clearer and easier to understand. The following will further elaborate on the present invention in detail in conjunction with the drawings and embodiments. The specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0027] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, wherein the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0028] Example 1 like Figure 1 -As shown in Figure 4, this embodiment provides a hybrid amplitude control method based on a grid-type inverter. A hybrid amplitude control method based on a grid-type inverter uses only P-ω droop control (GFM synchronous control) as synchronous control, but combines hybrid amplitude control to control current and voltage, thereby achieving stable operation of the system. The following is a specific implementation.

[0029] This embodiment is applied to a power grid system, the DC side voltage source is smoothed and filtered by a DC bus capacitor, stabilized, and then merged into the external power grid after passing through a three-phase converter and LCL filtering. The control method in this embodiment is applied to the power grid system.

[0030] First, the output current and the three-phase voltage of the three-phase converter on the input side of the power grid system are obtained, and power calculation is performed according to the output current and the three-phase voltage of the three-phase converter to obtain a first power P.

[0031] When calculating power based on the output current and three-phase voltage of the three-phase converter, the three-phase voltage used is the voltage value after LCL filtering; the three-phase current used is the current value after LCL filtering. In this embodiment, LCL filtering adopts LCL filter, which includes an inductor connected in series on the busbar. , voltage divider resistor 、Filter capacitor And the filter inductor on the grid side and resistor . Used to smooth the output voltage and reduce harmonics.

[0032] Perform P-ω droop control according to the first power to obtain a first frequency signal ω, and integrate the first frequency signal ω to obtain a first control signal .

[0033] Specifically, the first power P is used to synchronously control the input-side inverter and the load in the power grid system, and the response speed and power distribution are controlled by adjusting the droop coefficient m; The output frequency of the input side inverter is obtained as the first frequency P, and the first frequency is integrated by an integrator to obtain the first control signal required for the grid-connected control of the converter. .

[0034] P-ω droop control is a synchronous control method that mainly utilizes the relationship between power and frequency and reflects the change of load power by adjusting the output frequency of the inverter. Its working principle can be divided into the following steps: First, according to the P-ω droop characteristic, when the load power P1 of the inverter increases, the system frequency ω will decrease, and vice versa. In this way, the inverter responds to the load change by adjusting the output frequency.

[0035] In the P-ω droop control, the output frequency of the input-side inverter and the load power satisfy:

[0036] Where is the output frequency of the input-side inverter, is the rated frequency of the power grid system, is the droop coefficient, is the output power of the input-side inverter (expressed in per-unit value). In this embodiment, the rated frequency of the power grid system is 50Hz or 60Hz. The droop coefficient is mainly used to represent the frequency change caused by power change By adjusting the droop coefficient m, the response speed and power distribution of the power grid system can be controlled. Through the P-ω droop control, the output frequency ω of the inverter can be obtained, and then after integration, the phase information required for the grid connection control of the converter is generated (i.e., the first control signal ).

[0037] Furthermore, the three-phase current and three-phase voltage output by the three-phase converter are converted to the dq coordinate system, and hybrid amplitude control is performed on the three-phase voltage and three-phase current in the dq coordinate system to generate a second control signal for adjusting the voltage and current amplitudes.

[0038] Specifically, the rated reference value of the d-axis voltage and the rated reference value of the q-axis current are obtained; The three-phase voltage output by the three-phase converter is converted to the dq coordinate system to obtain the d-axis voltage component and the q-axis voltage component respectively. According to the d-axis voltage component and the rated reference value of the d-axis voltage, GFM amplitude control is performed to obtain the rated reference value of the d-axis current . Specifically, the d-axis component of the output voltage of the three-phase converter and the rated reference value of the d-axis voltage are used as the input of the outer voltage loop; the difference between the d-axis component of the output voltage of the three-phase converter and the rated reference value of the d-axis voltage is obtained, and after PI control, the rated reference value of the d-axis current is obtained; The three-phase current output by the three-phase converter After transformation to the dq coordinate system, the d-axis current component is obtained and the q-axis current component . According to the d-axis current component , the rated reference value of the d-axis current , the q-axis current component and the rated reference value of the q-axis current , GFL amplitude control is performed to obtain the d-axis voltage control signal and the q-axis voltage control signal respectively. Specifically, the q-axis current component of the output current of the three-phase converter , the rated reference value of the q-axis current are used as the inputs of the inner current loop; after subtracting the q-axis current component from the rated reference value of the q-axis current ( ), the q-axis control voltage signal is obtained through PI control; after subtracting the d-axis component of the output current of the three-phase converter from the rated reference value of the d-axis current output by the outer voltage loop ( ), the d-axis control voltage signal is obtained through PI control.

[0039] According to the d-axis control voltage signal , the q-axis control voltage signal and the first control signal , transformation to the abc coordinate system is performed to obtain the second control signal.

[0040] The control method of this embodiment has a simple structure, only through three PI controllers, and the parameter design is easy; on the premise of ensuring system stability, the synchronous frequency and phase are generated through P-ω droop control, realizing the controllability of the d-axis voltage and the q-axis current.

[0041] According to the second control signal, a modulation wave signal is obtained, and feedback control of the three-phase converter is performed according to the modulation wave signal. Specifically, after pulse width modulation of the second control signal, a modulation wave signal for driving the three-phase converter is obtained.

[0042] In this embodiment, this method is simulated through MATLAB / Simulink to verify the effectiveness of this method.

[0043] In the simulation model of the single-machine grid-connected system under MATLAB / Simulink, the specific control effect of the grid-forming converter under this synchronous control method is as Figure 3 shown. When the external infinite grid frequency drops from 1 p.u. to 0.99 p.u. at 1 s, the converter ( dq the output voltage of the system in the coordinate system), (dq The waveform diagrams of the output current of the system and the output frequency under the coordinate system). In the face of disturbance changes, the control method proposed in this embodiment can quickly achieve d axis voltage and q control of the axis current, keep it unchanged, and by changing q axis voltage and d axis current to maintain the stability of the system and not generate sub-synchronous oscillation and synchronous oscillation.

[0044] Figure 4 shows the waveform comparison diagram of the traditional grid-forming voltage-current double closed-loop control and the hybrid amplitude control method proposed in the present invention under the same parameter conditions. Among them, Figure 4 (a) is the waveform diagram of the traditional grid-forming double closed-loop control when the grid strength changes, and Figure 4 (b) is the waveform diagram of the proposed control. At 1.5 s, the impedance of the system drops from 0.2 p.u. to 0.08 p.u. (equivalent to an increase in grid strength). Under the same parameter conditions, only by changing the control method, it can be seen that under the traditional grid-forming double closed-loop control in Figure 4 (a), the system is unstable and an oscillation frequency of 19.1 Hz is generated. While the proposed hybrid amplitude control method in Figure 4 (b) can achieve stability and effectively improve the unstable characteristics of the grid-forming converter under strong grid conditions.

[0045] Embodiment 2 This embodiment provides a hybrid amplitude control system based on a grid-forming converter for implementing the hybrid amplitude control method based on a grid-forming converter in Embodiment 1. This system includes a data acquisition module, a power calculation module, a droop control module, a coordinate transformation module, and a hybrid amplitude control module. Each module specifically includes: A data acquisition module for acquiring the output current and three-phase voltage of the three-phase converter on the input side of the power grid system; A power calculation module for performing power calculation according to the output current and three-phase voltage of the three-phase converter to obtain the first power; A droop control module for performing P-ω droop control according to the first power to obtain a first frequency signal, and integrating the first frequency signal to obtain a first control signal; A coordinate transformation module for performing coordinate transformation on the output three-phase current and three-phase voltage of the three-phase converter to obtain the three-phase voltage and three-phase current in the dq coordinate system; A hybrid amplitude control module for performing hybrid amplitude control on the three-phase voltage and three-phase current in the dq coordinate system to generate a second control signal for adjusting the voltage and current amplitudes; obtaining a modulation wave signal according to the first control signal and the second control signal, and performing feedback control of the three-phase converter according to the modulation wave signal.

[0046] Embodiment 3 In an embodiment of the present invention, a computer-readable storage medium is provided. This medium belongs to the memory device of a terminal device and is mainly used to store programs and data. The computer-readable storage medium includes both the storage medium built into the terminal and the extended storage medium supported by the terminal. Specifically, any tangible medium that can store a program and be used by an instruction execution system, apparatus, or device belongs to this category. This storage medium provides storage space for storing the terminal operating system and instructions (including one or more computer programs and their codes) that can be loaded and executed by a processor. Examples include electrically connected devices, portable disks, hard disks, RAM, ROM, EPROM / flash memory, optical fibers, CD-ROMs, optical storage devices, magnetic storage devices, etc., and combinations thereof.

[0047] In addition, the computer-readable storage medium also relates to data signals propagated in a baseband or as a carrier wave. These signals carry readable program codes and can be in the form of electromagnetic signals, optical signals, etc. The readable storage medium is not limited to the above types and also includes other media that can send, propagate, or transmit a program for use by an instruction execution system, apparatus, or device. The program code can be transmitted via wireless, wired, optical fiber, RF, etc.

[0048] The program code can be written in a variety of programming languages, such as object-oriented languages (Python, Java, C++, etc.) and procedural languages (C language, etc.). The code can be executed completely or partially on a user device, or can be used as an independent software package, or can be executed partially / fully on a remote device. The remote device is connected to the user device via a LAN, WAN, or Internet service provider.

[0049] One or more instructions stored in the computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the hybrid amplitude control method based on a grid-forming converter in the above embodiment; one or more instructions in the computer-readable storage medium are loaded and executed by a processor to perform the following steps: Obtain the output current and three-phase voltage of the three-phase converter on the input side of the power grid system; Perform power calculation based on the output current and three-phase voltage of the three-phase converter to obtain the first power; Perform P-ω droop control based on the first power to obtain a first frequency signal, and integrate the first frequency signal to obtain a first control signal; Convert the output three-phase current and three-phase voltage of the three-phase converter to the dq coordinate system, and perform hybrid amplitude control on the three-phase voltage and three-phase current in the dq coordinate system to generate a second control signal for adjusting the amplitudes of the voltage and current; Obtain a modulation wave signal based on the first control signal and the second control signal, and perform feedback control of the three-phase converter according to the modulation wave signal.

[0050] Embodiment 4 As Figure 5 shown, the terminal device in this embodiment is a computer device 60, which mainly includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and running on the processor 61. When the computer program 63 is executed by the processor 61, the hybrid amplitude control method based on the grid-forming converter can be implemented, or the functions of each model / unit of the computing system of the power grid system in Embodiment 1 can be implemented, which will not be elaborated here.

[0051] The types of computer devices 60 are relatively diverse, including desktop computers, notebooks, palm computers, cloud servers, etc. Its components are not limited to the processor 61 and the memory 62, but may also include input / output devices, network access devices, buses, etc. Figure 5 Only as an example, the number and types of components of the actual device may vary.

[0052] The processor 61 can be a central processing unit (CPU), or other general-purpose processors, graphics processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) and other programmable logic devices, discrete gates, transistor logic devices, or even data processing logic devices based on quantum computing, discrete hardware components, etc., or can also be a conventional microprocessor.

[0053] Regarding the memory 62, it can be an internal storage unit of the computer device 60, such as a hard disk or memory, or an external storage device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card (FlashCard), etc. The memory 62 can also include both an internal storage unit and an external storage device, for storing computer programs, other required programs and data, and temporarily storing the data that has been output or to be output.

[0054] In each embodiment of the present application, the mentioned memory, database, or other media cover non-volatile and volatile memories. Non-volatile memories include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random-access memories (ReRAMs), magnetoresistive random-access memories (MRAMs), ferroelectric memories (FRAMs), phase-change memories (PCMs), graphene memories, etc.; volatile memories include random-access memory (RAM) or external cache memories, etc., and RAM can be further divided into various forms such as static random-access memory (SRAM) and dynamic random-access memory (DRAM).

Claims

1. A hybrid amplitude control method based on a grid-connected converter, characterized in that: include: Obtain output current and three-phase voltage of a three-phase converter on the input side of a power grid system; Perform power calculation according to the output current and the three-phase voltage of the three-phase converter to obtain a first power; Perform P-ω droop control according to the first power to obtain a first frequency signal, and integrate the first frequency signal to obtain a first control signal; Convert the three-phase current and three-phase voltage output by the three-phase converter to a dq coordinate system, perform mixed amplitude control on the three-phase voltage and three-phase current in the dq coordinate system, and generate a second control signal for adjusting the voltage and current amplitude; A modulated wave signal is obtained according to the first control signal and the second control signal, and feedback control of the three-phase converter is performed according to the modulated wave signal.

2. The hybrid amplitude control method based on a grid-connected converter according to claim 1, characterized in that: The method performs P-ω droop control according to the first power to obtain a first frequency signal, and obtains a first control signal after integrating the first frequency signal, specifically including: Using the first power to synchronously control the input-side inverter and the load in the power grid system, and controlling the response speed and power distribution by adjusting the droop coefficient; The output frequency of the input-side inverter is obtained as the first frequency, and the first frequency is integrated by an integrator to obtain a first control signal required for the grid-connected control of the converter.

3. The hybrid amplitude control method based on a grid-connected converter according to claim 2, characterized in that: In the P-ω droop control, the output frequency of the input side inverter and the load power satisfy: In the formula, is the output frequency of the input side inverter, is the rated frequency of the power grid system, is the droop coefficient, is the output power of the input side inverter.

4. The hybrid amplitude control method based on a grid-connected converter according to claim 1, characterized in that: The three-phase current and three-phase voltage output by the three-phase converter are converted to the dq coordinate system, and the three-phase voltage and three-phase current in the dq coordinate system are subjected to mixed amplitude control, specifically including: Obtain the d-axis voltage rated reference value and the q-axis current rated reference value; The three-phase voltage output by the three-phase converter is converted to the dq coordinate system to obtain the d-axis voltage component and the q-axis voltage component respectively, and the GFM amplitude is controlled according to the d-axis voltage component and the d-axis voltage rated reference value to obtain the d-axis current rated reference value; The three-phase current output by the three-phase converter is converted into a dq coordinate system to obtain a d-axis current component and a q-axis current component, and the GFL amplitude is controlled according to the d-axis current component, the d-axis current rated reference value, the q-axis current component and the q-axis current rated reference value to obtain a d-axis voltage control signal and a q-axis voltage control signal respectively; The d-axis voltage control signal, the q-axis voltage control signal and the first control signal are converted into the abc coordinate system to obtain a second control signal.

5. The hybrid amplitude control method based on a grid-connected converter according to claim 4, characterized in that: The GFM amplitude control and the GFL amplitude control respectively include: GFM amplitude control includes: taking the d-axis voltage component of the output voltage of the three-phase converter and the d-axis voltage rated reference value as voltage outer loop input; making a difference between the d-axis voltage component and the d-axis voltage rated reference value, and obtaining the d-axis current rated reference value after the difference is subjected to PI control; The GFL amplitude control includes: taking the q-axis current component of the three-phase converter output current and the q-axis current rated reference value as the current inner loop input; subtracting the q-axis current component from the q-axis current rated reference value, and obtaining the difference through PI control to obtain the q-axis control voltage signal; subtracting the d-axis current component from the d-axis current rated reference value output by the voltage outer loop, and obtaining the difference through PI control to obtain the d-axis control voltage signal.

6. The hybrid amplitude control method based on a grid-connected converter according to claim 1, characterized in that: When the power is calculated based on the output current and the three-phase voltage of the three-phase converter, the three-phase voltage used is the voltage value after LCL filtering; the three-phase current used is the current value after LCL filtering.

7. The hybrid amplitude control method based on a grid-connected converter according to claim 4, characterized in that: After the second control signal is pulse width modulated, a modulation wave signal for driving the three-phase converter is obtained.

8. A hybrid amplitude control system based on a grid-type converter, used to implement the hybrid amplitude control method based on a grid-type converter according to any one of claims 1 to 7, characterized in that: include: A data acquisition module, used to acquire the output current and three-phase voltage of the three-phase converter on the input side of the power grid system; A power calculation module, used to perform power calculation according to the output current and the three-phase voltage of the three-phase converter to obtain a first power; A droop control module, configured to perform P-ω droop control according to the first power to obtain a first frequency signal, and integrate the first frequency signal to obtain a first control signal; A coordinate transformation module is used to perform coordinate transformation on the three-phase current and three-phase voltage output by the three-phase converter to obtain the three-phase voltage and three-phase current in the dq coordinate system; The hybrid amplitude control module is used to perform hybrid amplitude control on the three-phase voltage and three-phase current in the dq coordinate system, generate a second control signal for adjusting the voltage and current amplitudes; obtain a modulated wave signal according to the first control signal and the second control signal, and perform feedback control of the three-phase converter according to the modulated wave signal.

9. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions, which, when executed by a computing device, enable the computing device to execute the hybrid amplitude control method based on a grid-type converter as claimed in any one of claims 1 to 7.

10. A computing device, characterized in that include: One or more processors, a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include steps for executing the hybrid amplitude control method based on a grid-type converter as described in any one of claims 1 to 7.

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