Micro-grid dynamic frequency adjusting method and system based on alternating current and direct current networking equipment

Abstract

The invention belongs to the technical field of micro-grid regulation and control, and provides a micro-grid dynamic frequency regulation method and system based on alternating current and direct current networking equipment, and the method comprises the steps: rapidly determining the state of each micro-grid and the frequency regulation coefficient of each micro-grid through a frequency deviation value between a theoretical output frequency and an actual output frequency of a VSC corresponding to each micro-grid; and by adding a frequency active compensation item designed based on a frequency adjustment coefficient, a virtual synchronous generator control strategy corresponding to the VSC is optimized, so that the method can adapt to frequency adjustment characteristics of different microgrids, and the efficiency and accuracy of dynamically adjusting the frequency of each microgrid can be effectively improved. Besides, after the frequency of each micro-grid is adjusted, the output current of the energy storage equipment is quickly adjusted through the direct current voltage stabilization converter, so that normal operation of the alternating current and direct current networking equipment and each micro-grid load can be ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of micro-grid regulation, and more particularly, relates to a micro-grid dynamic frequency regulation method and system based on AC-DC networking equipment. BACKGROUND

[0002] Under the background of energy transformation, the distribution network is experiencing a transition from one-way power supply to active distribution network with high proportion of new energy access. To further improve power supply reliability, the method of independently forming a micro-grid station area at the end of the distribution network during power grid failure has been widely used. At present, due to a large number of distributed photovoltaic power generation equipment and energy storage equipment being connected to the user side of the micro-grid distribution network, the power fluctuation of the micro-grid station area is serious, which may cause the frequency stability of the micro-grid to be severely damaged, The existing AC-DC networking equipment connected with multiple micro-grids in the distribution area has limited frequency regulation effect on micro-grids in different scenarios, and cannot effectively perform real-time dynamic frequency regulation on multiple micro-grids connected in parallel. It is also difficult to quickly adjust the AC-DC networking equipment to a stable working state after frequency regulation on a large number of micro-grids. SUMMARY

[0003] In view of the above defects in the prior art, the present application provides a micro-grid dynamic frequency regulation method and system based on AC-DC networking equipment, aiming to solve the problems of poor regulation effect and unstable DC voltage state of the equipment when the existing AC-DC networking equipment is used to regulate the frequency of the micro-grid.

[0004] In a first aspect, the present application provides a micro-grid dynamic frequency regulation method based on AC-DC networking equipment, applied to a low-voltage coordinated control unit of the AC-DC networking equipment, the AC-DC networking equipment comprising a DC voltage stabilizing converter, an energy storage device and multiple VSCs (Voltage Source Converter, voltage source converter), the method comprising: obtaining the theoretical output frequency and the actual output frequency of the VSC corresponding to each micro-grid; judging the operating state of each micro-grid based on the frequency deviation value of the theoretical output frequency and the actual output frequency corresponding to each micro-grid; adjusting the actual output frequency of the VSC corresponding to each micro-grid based on the operating state and the frequency deviation value corresponding to each micro-grid; adjusting the output current of the energy storage device through the DC voltage stabilizing converter based on the actual DC voltage of the frequency-regulated AC-DC networking equipment.

[0005] Further, judging the operating state of each micro-grid comprises: determining the operating state of the micro-grid based on the comparison result of the frequency deviation value corresponding to the micro-grid and the first preset value and the second preset value. The micro-grid is in a normal state when the frequency deviation value is not greater than a first preset value, the micro-grid is in a micro-risk state when the frequency deviation value is greater than the first preset value and less than a second preset value, and the micro-grid is in a full-risk state when the frequency deviation value is greater than the second preset value.

[0006] Since the AC / DC networking equipment applied in the present application is used for frequency regulation of multiple micro-grids, and the states of the micro-grids are quite different, if all are processed according to the same operation state, the regulation efficiency will be quite different. Therefore, different strategies are adopted for frequency regulation according to the risk degree of the micro-grid, which can improve the frequency regulation efficiency of the corresponding VSC of the micro-grid.

[0007] Further, the actual output frequency of the VSC corresponding to each micro-grid is regulated, including: determining a frequency regulation coefficient of the VSC corresponding to the micro-grid based on the operation state of the micro-grid; regulating the actual output frequency of the VSC corresponding to the micro-grid through an improved virtual synchronous generator control strategy based on the frequency regulation coefficient of the VSC corresponding to the micro-grid and the frequency deviation value.

[0008] Further, the formula for determining the frequency regulation coefficient of the VSC corresponding to the micro-grid is:

[0009] wherein, K f the frequency regulation coefficient of the VSC is represented by K, the frequency deviation value is represented by Δf, and the initial frequency regulation coefficient of the VSC is represented by K0. f the frequency deviation value is represented by Δf, f band1 , f band2 the first preset value and the second preset value are represented by f1 and f2 respectively, K f0 the initial frequency regulation coefficient of the VSC is represented by K0.

[0010] The present application sets the first preset value and the second preset value according to the characteristics of the AC / DC networking equipment, and then the operation state and the corresponding frequency regulation coefficient of the micro-grid can be quickly determined according to the frequency deviation value of the micro-grid, thereby effectively improving the frequency regulation effect of the micro-grid.

[0011] Further, the actual output frequency of the VSC corresponding to the micro-grid is regulated through the improved virtual synchronous generator control strategy, including: the output frequency of the VSC is simulated by the rotor angular frequency of the virtual synchronous generator, the rotor inertia of the synchronous generator is simulated by the virtual moment of inertia, and the output rotor angular frequency includes the actual rotor angular frequency and the theoretical rotor angular frequency; The theoretical active power and the actual active power of the VSC are obtained, and the actual output frequency of the VSC is obtained based on the frequency regulation coefficient, the theoretical active power and the actual active power.

[0012] Further, the formula for obtaining the actual output frequency of the VSC is as follows: ; Wherein, J represents a virtual inertia coefficient, Kf represents a frequency regulation coefficient, Dp represents a damping coefficient, ω and ωn respectively represent the actual rotor angular frequency and the theoretical rotor angular frequency, Pref and Pvsc respectively represent the theoretical active power and the actual active power, θ represents the voltage phase corresponding to the VSC, and the actual rotor angular frequency corresponds to the actual output frequency.

[0013] The present application adds a frequency active compensation term on the basis of the existing virtual synchronous generator control strategy K f ( ω n - ω ), cooperates with the frequency regulation coefficient obtained in the above steps Kf , and can dynamically adjust the actual output frequency of the VSC according to the range of the VSC frequency deviation value of the microgrid, thereby improving the efficiency and accuracy of the frequency regulation of the microgrid by the present application.

[0014] Further, the output current of the energy storage device is adjusted by the DC voltage stabilizing converter, and the formula for the output current of the energy storage device is as follows: ; Wherein, U dcref and U dc respectively represent the rated DC voltage and the actual DC voltage of the AC-DC networking equipment, I Lref represents the rated output current value of the energy storage device, I L represents the actual output current value of the energy storage device after being adjusted by the DC voltage stabilizing converter, d represents the duty cycle of the DC voltage stabilizing converter, k p1 and k i1 respectively represent U dcref the corresponding proportional coefficient and integral coefficient, k p2 andk i2 respectively represent I Lref The corresponding proportional coefficient and integral coefficient.

[0015] Since the number of microgrids that need to be adjusted by AC-DC networking equipment is large, adjusting the frequency of the microgrid through the corresponding VSC of the microgrid will cause serious oscillation of the DC voltage of the AC-DC networking equipment, affecting the safety and service life of the equipment. Therefore, adjusting the output current of the energy storage device through the DC voltage stabilizing converter according to the above formula can quickly maintain a stable working state, thereby improving the service life of the AC-DC networking equipment and the loads in each microgrid.

[0016] In a second aspect, the present application also provides a microgrid dynamic frequency adjustment system based on AC-DC networking equipment, which is applied to a low-voltage cooperative control unit of the AC-DC networking equipment and is used to implement any method of the first aspect, and includes: a microgrid frequency acquisition unit, configured to acquire the theoretical output frequency and the actual output frequency of the VSC corresponding to the microgrid; a state analysis module, configured to determine the operating state of each microgrid; a frequency adjustment unit, configured to adjust the actual output frequency of the VSC corresponding to each microgrid; a DC voltage stabilizing module, configured to adjust the output current of the energy storage device through the DC voltage stabilizing converter after the frequency adjustment unit adjusts the actual output frequency of each VSC.

[0017] In a third aspect, the present application also provides an electronic device, including at least one memory for storing a program, and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute the method described in any possible implementation manner of the first aspect.

[0018] In a fourth aspect, the present application also provides a computer-readable storage medium, which stores a computer program, and when the computer program runs on the processor, the processor executes the method described in the first aspect or any possible implementation manner of the first aspect.

[0019] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art: the present application provides a method and system for dynamic frequency regulation of a microgrid based on AC / DC networking equipment, which quickly determines the status of each microgrid and the frequency regulation coefficient of each microgrid by the frequency deviation value between the theoretical output frequency and the actual output frequency of the VSC corresponding to each microgrid, and optimizes the control strategy of the virtual synchronous generator corresponding to the VSC by adding a frequency active compensation term designed based on the frequency regulation coefficient, thereby being able to adapt to the frequency regulation characteristics of different microgrids, thereby effectively improving the efficiency and accuracy of the present application in dynamically regulating the frequency of each microgrid. In addition, after adjusting the frequency of each microgrid, the present application quickly adjusts the output current of the energy storage device through the DC voltage-stabilizing converter, thereby ensuring the normal operation of the AC / DC networking equipment and the loads of each microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments or related technical descriptions one by one. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a flow chart of a method for dynamic frequency regulation of a microgrid based on AC / DC networking equipment provided in an embodiment of the present application.

[0022] Figure 2 An embodiment of the present application provides a schematic diagram of a working state of AC / DC networking equipment.

[0023] Figure 3 A schematic structural diagram of a microgrid dynamic frequency regulation system based on AC / DC networking equipment is provided in an embodiment of the present application.

[0024] Figure 4 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0026] In the following description, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance. The following description provides a plurality of embodiments of the present application, which can be replaced or combined with each other, so that the present application can also be considered to include all possible combinations of the same and / or different embodiments described. Therefore, if one embodiment includes features A, B, C, and another embodiment includes features B, D, the present application should also be considered to include embodiments containing one or more of all other possible combinations of A, B, C, and D, although such embodiments can not be explicitly described in the following.

[0027] The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes can be made to the functions and arrangements of described elements without departing from the scope of the present application. Various examples can appropriately omit, replace or add various processes or components. For example, the described methods can be performed in a different order from the described order, and various steps can be added, omitted or combined. In addition, features described with respect to some examples can be combined into other examples.

[0028] Figure 1 is a flowchart of a micro-grid dynamic frequency regulation method based on AC-DC networking equipment provided by the embodiments of the present application, as Figure 1 shown, applied to a low-voltage cooperative control unit of AC-DC networking equipment, the AC-DC networking equipment includes a DC voltage stabilizing converter, an energy storage device and a plurality of VSCs. The method at least includes the following steps: S1, obtaining the theoretical output frequency and the actual output frequency of the VSC corresponding to each micro-grid.

[0029] In the embodiments of the present application, as Figure 2 shown, the execution subject of the present method can be the MCU (Microcontroller Unit, microcontroller) of the low-voltage cooperative control unit integrating the method of the embodiments. The low-voltage cooperative control unit can be connected with the corresponding storage device, and thus can obtain the theoretical output frequency of the VSC corresponding to each micro-grid from the storage device.

[0030] S2, judging the operating state of each micro-grid based on the frequency deviation value of the theoretical output frequency and the actual output frequency corresponding to each micro-grid.

[0031] In the embodiments of the present application, the purpose of judging the operating state of each micro-grid is to quickly determine the corresponding frequency regulation strategy according to the frequency deviation value of the micro-grid.

[0032] In one implementation manner, judging the operating state of each micro-grid includes: determine the operation state of the micro-grid based on a comparison result of the frequency deviation value corresponding to the micro-grid and the first preset value and the second preset value; The micro-grid is in a normal state when the frequency deviation value is not greater than the first preset value, in a micro-risk state when the frequency deviation value is greater than the first preset value and less than the second preset value, and in a full-risk state when the frequency deviation value is greater than the second preset value.

[0033] In the embodiments of the present application, the first preset value and the second preset value can be set according to the actual device properties of the AC-DC networking equipment or the frequency range of the normal operation of the micro-grid according to the national standard. For example, in the national standard, the frequency deviation range of the normal operation of the micro-grid is 0 to 0.05 HZ, and the frequency deviation out-of-limit standard line of the micro-grid is 0.1 HZ. Therefore, for the micro-grid in the micro-risk state, the frequency regulation range is relatively small, and for the micro-grid in the full-risk state, a large frequency regulation strategy is needed to quickly adjust. Therefore, different strategies are adopted for frequency regulation according to the risk degree of the micro-grid, which can improve the frequency regulation efficiency of the VSC corresponding to the micro-grid.

[0034] S3, adjusting the actual output frequency of the VSC corresponding to each micro-grid based on the operation state and the frequency deviation value corresponding to each micro-grid.

[0035] In one implementation manner, adjusting the actual output frequency of the VSC corresponding to each micro-grid comprises: determining the frequency regulation coefficient of the VSC corresponding to the micro-grid based on the operation state corresponding to the micro-grid; adjusting the actual output frequency of the VSC corresponding to the micro-grid by the improved virtual synchronous generator control strategy based on the frequency regulation coefficient corresponding to the micro-grid and the frequency deviation value.

[0036] In the embodiments of the present application, the virtual synchronous generator control strategy simulates the primary frequency regulation characteristics of the synchronous machine by using the droop control, which can realize the fast frequency regulation of the VSC. At the same time, the control strategy can adjust the amplitude and phase of the output voltage, which can not only control the frequency but also participate in the reactive power regulation, improve the voltage stability of the power grid, and reduce the harmonic distortion. The damping control link of the strategy can simulate the damping torque of the synchronous machine, and when the system is disturbed (such as short-circuit fault and large load switching), the rotor angle oscillation is suppressed by adjusting the electromagnetic power, thereby reducing the frequency fluctuation. Therefore, the virtual synchronous generator control strategy is adopted in the embodiments and is improved to adapt to the VSC of different micro-grids.

[0037] In one implementation manner, the formula for determining the frequency regulation coefficient of the VSC corresponding to the micro-grid is:

[0038] wherein,K f denotes a frequency regulation coefficient of the VSC, f denotes a frequency deviation value, f band1 、 f band2 respectively denote a first preset value and a second preset value, K f0 denotes an initial frequency regulation coefficient of the VSC.

[0039] In the embodiments of the present application, when the frequency deviation value of the micro-grid is greater than the second preset value, a double initial frequency regulation coefficient is directly used as the frequency regulation coefficient of the VSC, so as to quickly reduce the frequency of the corresponding micro-grid to a safe range, and then the secondary frequency regulation can be performed according to the above method. In this way, the regulation efficiency of the method of the embodiments on the frequency of the micro-grid can be improved.

[0040] In an implementable manner, the actual output frequency of the VSC corresponding to the micro-grid is regulated by the improved virtual synchronous generator control strategy, including: the output frequency of the VSC is simulated by the rotor angular frequency of the virtual synchronous generator, the rotor inertia of the synchronous generator is simulated by the virtual moment of inertia, and the output rotor angular frequency includes an actual rotor angular frequency and a theoretical rotor angular frequency; the theoretical active power and the actual active power of the VSC are obtained, and the actual output frequency of the VSC is obtained based on the frequency regulation coefficient, the theoretical active power and the actual active power.

[0041] In the embodiments of the present application, the formula for obtaining the actual output frequency of the VSC is as follows: ; wherein, J denotes a virtual inertia coefficient, Kf denotes a frequency regulation coefficient, Dp denotes a damping coefficient, ω and ωn respectively denote an actual rotor angular frequency and a theoretical rotor angular frequency, Pref and Pvsc respectively denote a theoretical active power and an actual active power, θ denotes a voltage phase corresponding to the VSC, and the actual rotor angular frequency corresponds to the actual output frequency.

[0042] In the embodiments of the present application, the improved virtual synchronous generator control strategy selected in the present instance is to add a frequency active compensation term to the virtual synchronous generator control strategy K f ω n ω ​​). Since the frequency response speed of the existing virtual synchronous generator control strategy is limited by the mechanical inertia analog quantity (such as J , the larger the frequency change is slower), and the frequency modulation effect of the microgrid in different operating environments is greatly deviated. Therefore, the frequency active compensation term K f ( ω n - ω ) can be an improved virtual synchronous generator control strategy, which can be applied to different microgrids, and can synchronize, accurately and quickly adjust the actual output frequency of the VSC of multiple microgrids through the low-voltage coordinated control unit of the AC-DC networking equipment.

[0043] S4, based on the frequency-adjusted actual DC voltage of the AC-DC networking equipment, the output current of the energy storage device is adjusted through the DC voltage stabilizing converter.

[0044] In an implementation manner, the output current of the energy storage device is adjusted through the DC voltage stabilizing converter, and the formula of the output current of the energy storage device is as follows: ; Among them, U dcref and U dc respectively represent the rated DC voltage and the actual DC voltage of the AC-DC networking equipment, I Lref represents the rated output current value of the energy storage device, I L represents the actual output current value of the energy storage device after being adjusted by the DC voltage stabilizing converter, d represents the duty cycle of the DC voltage stabilizing converter, k p1 and k i1 respectively represent U dcref corresponding proportional coefficient and integral coefficient, k p2 and k i2 respectively represent I Lref corresponding proportional coefficient and integral coefficient.

[0045] In the embodiments of the present application, the output current of the energy storage device is adjusted through the DC voltage stabilizing converter, mainly to quickly and smoothly adjust the DC voltage of the AC-DC networking equipment, quickly eliminate the voltage oscillation generated in the frequency regulation process of each microgrid, and then meet the energy supply demand of the VSC when the frequency of multiple microgrids is dynamically adjusted, thereby ensuring the normal work of the load of each microgrid.

[0046] Figure 3 A structural diagram of a micro-grid dynamic frequency regulation system based on AC-DC networking equipment is provided in the embodiments of the present application. The system is applied to a low-voltage cooperative control unit of AC-DC networking equipment, as shown in the figure. The system at least includes: Figure 3 a micro-grid frequency acquisition unit, configured to acquire a theoretical output frequency and an actual output frequency of a VSC corresponding to the micro-grid; a state analysis module, configured to determine an operating state of each micro-grid; a frequency regulation unit, configured to regulate the actual output frequency of the VSC corresponding to each micro-grid; a DC voltage stabilization module, configured to regulate an output current of an energy storage device through a DC voltage stabilization converter after the frequency regulation unit regulates the actual output frequency of each VSC.

[0047] As shown in the figure, Figure 4 Figure 4 is a structural diagram of an electronic device provided in the embodiments of the present application. The electronic device can include a processor 401, a communications interface 402, a memory 403, and a communications bus 404. The processor 401, the communications interface 402, and the memory 403 can complete mutual communication through the communications bus 404. The processor 401 can invoke software instructions in the memory 403 to execute the methods described in the above embodiments.

[0048] In addition, the logical instructions in the memory 403 described above can be implemented in the form of a software function unit and sold or used as an independent product. When used, the logical instructions can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the embodiments of the present application.

[0049] Based on the methods in the above embodiments, the embodiments of the present application provide a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the methods in the above embodiments.

[0050] Based on the methods in the above embodiments, the embodiments of the present application provide a computer program product. When the computer program product runs on a processor, the processor executes the methods in the above embodiments.

[0051] ​​It can be understood that the processor in the embodiments of the present application can be a CPU (Central Processing Unit), and can also be other general-purpose processors, DSPs (Digital Signal Processors), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor, or any conventional processor.

[0052] The method steps in the embodiments of the present application can be implemented in a hardware manner, or in a manner of executing software instructions by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random RAM (Random Access Memory), a flash memory, a ROM (Read-only Memory), a PROM (Programmable ROM), an EPROM (Erasable PROM), an EEPROM (Electrically EPROM), a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC.

[0053] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in or transmitted from a computer readable storage medium. The computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through a wired (such as coaxial cable, optical fiber, digital subscriber line DSL) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as an SSD (Solid State Disk)), etc.

[0054] It can be understood that various numerical numbers involved in the embodiments of the present application are only distinguished for convenience of description, and are not used to limit the scope of the embodiments of the present application.

[0055] Those skilled in the art easily understand that the above are only preferred embodiments of the present application, and are not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for dynamic frequency regulation of a microgrid based on AC / DC network equipment, characterized in that, The application relates to a low-voltage coordination unit applied to AC-DC networking equipment, wherein the AC-DC networking equipment comprises a DC voltage stabilizing converter, energy storage equipment and a plurality of VSCs, and the method comprises the following steps: acquiring theoretical output frequencies and actual output frequencies of the VSCs corresponding to each micro-grid; judging the operation states of each micro-grid based on frequency deviation values of the theoretical output frequencies and the actual output frequencies corresponding to each micro-grid; adjusting the actual output frequencies of the VSCs corresponding to each micro-grid based on the operation states and the frequency deviation values corresponding to each micro-grid; adjusting the output current of the energy storage equipment through the DC voltage stabilizing converter based on the actual DC voltage of the frequency-adjusted AC-DC networking equipment.

2. The method of claim 1, wherein the AC / DC based microgrid dynamic frequency regulation method is characterized by, The judgment of the operation states of each micro-grid comprises the following steps: determining the operation state of the micro-grid based on the comparison result of the frequency deviation value corresponding to the micro-grid and first and second preset values; wherein the micro-grid is in a normal state when the frequency deviation value is not greater than the first preset value, the micro-grid is in a micro-risk state when the frequency deviation value is greater than the first preset value and less than the second preset value, and the micro-grid is in a full-risk state when the frequency deviation value is greater than the second preset value. 3.The method of claim 2, wherein, The adjustment of the actual output frequencies of the VSCs corresponding to each micro-grid comprises the following steps: determining the frequency adjustment coefficient of the VSC corresponding to the micro-grid based on the operation state of each micro-grid; adjusting the actual output frequency of the VSC corresponding to the micro-grid through an improved virtual synchronous generator control strategy based on the frequency adjustment coefficient and the frequency deviation value.

4. The method of claim 3, wherein the AC / DC based microgrid dynamic frequency regulation method is characterized by, The formula for determining the frequency adjustment coefficient of the VSC corresponding to the micro-grid is as follows: wherein, K f represents a frequency regulation coefficient of the VSC, Δ f represents the frequency deviation value, f band1 , f band2 respectively represent the first preset value and the second preset value, K f0 represents an initial frequency regulation coefficient of the VSC.

5. The method of claim 4, wherein the AC / DC based microgrid dynamic frequency regulation method is characterized by, The adjustment of the actual output frequency of the VSC corresponding to the micro-grid through the improved virtual synchronous generator control strategy comprises the following steps: simulating the output frequency of the VSC through a rotor angular frequency of a virtual synchronous generator, simulating the rotor inertia of a synchronous generator through virtual rotational inertia, and the output rotor angular frequency comprises an actual rotor angular frequency and a theoretical rotor angular frequency; acquiring theoretical active power and actual active power of the VSC, and acquiring the actual output frequency of the VSC based on the frequency adjustment coefficient, the theoretical active power and the actual active power.

6. The method of claim 5, wherein the AC-DC based microgrid dynamic frequency regulation method is characterized by, The formula for acquiring the actual output frequency of the VSC is as follows: ； wherein, J represents a virtual inertia coefficient, Kf represents a frequency regulation coefficient, Dp represents a damping coefficient, ω and ωn respectively represent an actual rotor angular frequency and a theoretical rotor angular frequency, Pref and Pvsc respectively represent a theoretical active power and an actual active power, θ represents a voltage phase corresponding to the VSC, the actual rotor angular frequency corresponding to the actual output frequency.

7. The method of claim 1, wherein the AC / DC based microgrid dynamic frequency regulation method further comprises: The formula for adjusting the output current of the energy storage equipment through the DC voltage stabilizing converter is as follows: ； wherein, U dcref and U dc respectively represent the rated DC voltage and the actual DC voltage of the AC / DC networking equipment, I Lref represents the rated output current value of the energy storage device, I L represents the actual output current value of the energy storage device after being adjusted by the DC voltage stabilizing converter, d represents the duty cycle of the DC voltage stabilizing converter, k p1 and k i1 respectively represent U dcref corresponding proportional coefficient and integral coefficient, k p2 and k i2 respectively represent I Lref corresponding proportional coefficient and integral coefficient.

8. A microgrid dynamic frequency regulation system based on AC / DC networking equipment, applied to a low-voltage cooperative control unit of AC / DC networking equipment, used to implement the method of any one of claims 1-7, characterized in that, comprises the following steps: a micro-grid frequency acquisition unit is used to acquire theoretical output frequencies and actual output frequencies of VSCs corresponding to a micro-grid; a state analysis module is used to determine the operation states of each micro-grid; a frequency adjustment unit is used to adjust the actual output frequencies of the VSCs corresponding to each micro-grid; a DC voltage stabilizing module is used to adjust the output current of the energy storage equipment through a DC voltage stabilizing converter after the actual output frequencies of each VSC are adjusted by the frequency adjustment unit.

9. An electronic device, comprising: comprises the following steps: at least one memory for storing a computer program; at least one processor for executing the program stored by the memory, the processor being configured to perform the method according to any one of claims 1 to 7 when the program stored by the memory is executed.

10. A computer-readable storage medium having stored thereon a computer program, the computer-readable storage medium having stored therein instructions, characterized in that, computer program for performing the method according to any one of claims 1 to 7 when the program is executed on a computer or processor.

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