Micro-grid instantaneous energy hierarchical regulation and control method

Abstract

The invention relates to the technical field of micro-grid instantaneous energy hierarchical regulation and control, and discloses a micro-grid instantaneous energy hierarchical regulation and control method, which comprises the steps of setting a hierarchical limit value of a micro-grid instantaneous energy balance index; dC side voltage values and current values of all converters in the microgrid are detected in real time, and an instantaneous energy balance index value of the microgrid is calculated; judging the instantaneous energy balance index value of the micro-grid, and judging whether the instantaneous energy per unit value of the micro-grid exceeds the limit or not; and if it is judged that large disturbance or fault occurs in the micro-grid, the micro-grid stops running. The method not only helps to guarantee safe and stable operation of the microgrid, but also helps to improve the absorption capability of the microgrid to the distributed power supply.

Description

Technical Field

[0001] This invention relates to the field of microgrid instantaneous energy hierarchical regulation technology, and in particular to a method for microgrid instantaneous energy hierarchical regulation. Background Technology

[0002] The integration of distributed power sources such as photovoltaics and wind power, as well as fluctuating loads like electric vehicles, introduces greater volatility, time-varying characteristics, and randomness into microgrid systems. Therefore, ensuring real-time energy balance during microgrid operation is a key challenge for its safe and stable operation. However, there is currently no literature defining how to measure energy balance within a microgrid system. Simultaneously, the instantaneous energy balance index is another crucial issue that microgrid management systems must address to better achieve dynamic management of energy balance among various distributed power sources, energy storage systems, and flexible loads within the microgrid. Therefore, a critical challenge for current microgrid energy management systems is selecting the appropriate instantaneous energy balance index and implementing rapid regulation and dynamic management of energy between sources, loads, and storage based on this index, thereby ensuring the safe and stable operation of the microgrid. Summary of the Invention

[0003] In view of the aforementioned existing problems, the present invention is proposed.

[0004] Therefore, this invention provides a microgrid instantaneous energy hierarchical control method, which realizes hierarchical control of system energy based on the instantaneous energy balance index value of the microgrid, enables rapid judgment of whether a fault has occurred in the microgrid causing the DC voltage of the converter to exceed the limit, and effectively ensures the safe and stable operation of the converter in the microgrid.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for instantaneous energy hierarchical regulation of a microgrid, comprising:

[0006] Set tiered limits for the instantaneous energy balance index of microgrids;

[0007] Real-time monitoring of DC-side voltage and current values ​​of all converters in the microgrid, and calculation of the instantaneous energy balance index value of the microgrid;

[0008] Determine whether the instantaneous energy balance index value of the microgrid, the instantaneous energy per unit value of the microgrid exceeds the limit;

[0009] If a large disturbance or fault is detected in the microgrid, the microgrid will be shut down.

[0010] As a preferred embodiment of the microgrid instantaneous energy tiered control method described in this invention, the step of setting the tiered limit values ​​for the microgrid instantaneous energy balance index includes obtaining the rated DC voltage and capacitance values ​​of all converters in the involved microgrid. Assuming there are n converters in the microgrid, the rated DC voltage of the k-th converter is... The DC side capacitor value is where k = 1, 2, ..., n;

[0011] Assume the voltage on the DC side of the k-th converter in the microgrid is... Then the instantaneous energy per unit value of the k-th converter Calculate using the following formula:

[0012]

[0013] The instantaneous energy balance index of the microgrid is set as the weighted average of the instantaneous energy on the DC side of all converters in the microgrid. The weighting factor for the instantaneous energy of each converter is: The instantaneous energy balance index of the microgrid The mathematical expression is as follows:

[0014]

[0015] Set microgrid instantaneous energy balance index The tiered limits, the instantaneous energy balance index of microgrids The tiered limits include those for microgrids during normal operation. The upper and lower limits are respectively , and during normal working hours The maximum and minimum allowed values ​​are respectively , .

[0016] As a preferred embodiment of the microgrid instantaneous energy level control method of the present invention, wherein: the setting of the level limit value of the microgrid instantaneous energy balance index includes the microgrid instantaneous energy balance index The relationship between the four limits is as follows: < < < ;

[0017] Regarding the selection of graded limits for the microgrids involved, the instantaneous energy balance index of the microgrid under different operating conditions is calculated or simulated. The values ​​are based on the instantaneous energy balance index of the microgrid calculated and simulated under different operating conditions. Values ​​are used to determine the instantaneous energy balance index of the microgrid. The numerical values ​​of the four limits.

[0018] As a preferred embodiment of the microgrid instantaneous energy hierarchical control method described in this invention, the calculation of the microgrid instantaneous energy balance index value includes real-time detection and acquisition of the DC-side voltage and current values ​​of all converters in the involved microgrid, wherein the DC-side voltage value of the k-th converter in the microgrid is... The current value is ;

[0019] Calculate the instantaneous energy balance index of the microgrid based on the DC-side voltage values ​​of each converter in the microgrid. value;

[0020] Based on the DC-side voltage value of the k-th converter in the microgrid Current value Calculate the DC-side power of the k-th converter. ,Right now ,pass The sign of the value determines the direction of energy inflow and outflow within the k-th converter.

[0021] Obtain the DC-side power of the converter connected to the flexible load in the microgrid, and determine the adjustable capacity of the flexible load based on the current power and capacity of the flexible load;

[0022] The state of charge (SOC) of the batteries in the energy storage device in the microgrid and the DC-side power of the converter connected to the energy storage device are obtained, and the available adjustable capacity of the energy storage battery is determined based on the SOC value of the energy storage device.

[0023] As a preferred embodiment of the microgrid instantaneous energy hierarchical control method of the present invention, the step of determining whether the microgrid instantaneous energy balance index value, the microgrid instantaneous energy balance index value, and the microgrid instantaneous energy per-unit value exceeds the limit includes,

[0024] Determine the instantaneous energy balance index value of the microgrid Are the upper and lower limits during normal operation? , Between, that is ≤ ≤ If the condition is met, return to the previous step; otherwise, proceed to the next step.

[0025] If the instantaneous energy balance index value of the microgrid Upper and lower limits during normal operation , If the conditions are not met, no additional adjustment is needed to the power command of the microgrid converter; otherwise, proceed to the next step.

[0026] As a preferred embodiment of the microgrid instantaneous energy level control method of the present invention, the step of judging whether the microgrid instantaneous energy balance index value, the microgrid instantaneous energy balance index value, and judging whether the microgrid instantaneous energy per-unit value exceeds the limit includes judging the microgrid instantaneous energy balance index value. Is it less than the maximum limit allowed during normal operation? ,Right now The values ​​satisfy the following relationship < < ;

[0027] If the instantaneous energy balance index value of the microgrid Less than the maximum limit allowed during normal operation and greater than If so, the priority is to restore the instantaneous energy balance of the microgrid by adjusting the power command of the converter connected to the flexible load, and then consider restoring the instantaneous energy balance of the microgrid by adjusting the power command of the converter of the energy storage device. There are three operation schemes for restoring the instantaneous energy balance of the microgrid.

[0028] The first approach involves selecting a flexible load converter with adjustable capacity based on the adjustable capacity of the flexible loads in the microgrid. This adjusts the active power command in the outer loop of the flexible load converter, increasing the active power flowing out of the microgrid and thus improving the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0029] The second approach involves adjusting the outer-loop active power command of the energy storage device's converter based on its adjustable capacity, enabling the energy storage device to absorb excess energy from the microgrid. In this case, the microgrid's instantaneous energy balance index value... Return to the upper and lower limits that are in normal operation of the microgrid;

[0030] The third approach involves adjusting the power commands of flexible load converters and energy storage converters with adjustable capacity to adjust the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0031] If the above conditions are not met, proceed to the next step.

[0032] As a preferred embodiment of the microgrid instantaneous energy hierarchical control method of the present invention, the step of judging whether the microgrid instantaneous energy balance index value, the microgrid instantaneous energy balance index value, and the microgrid instantaneous energy per-unit value exceeds the limit includes judging the microgrid instantaneous energy per-unit value. Is it greater than the minimum allowable value during normal operation? ,Right now The value range satisfies the following relationship < < ;

[0033] If the instantaneous energy balance index value of the microgrid Greater than the minimum allowable value during normal operation ,Right now The values ​​satisfy the following relationship < < If so, the priority is to restore the instantaneous energy balance of the microgrid by adjusting the power command of the flexible load grid-connected converter, and then consider restoring the instantaneous energy balance of the microgrid by adjusting the power command of the energy storage device converter. There are three operation schemes for restoring the instantaneous energy balance of the microgrid.

[0034] The first approach involves selecting a flexible load converter with adjustable capacity based on the adjustable capacity of the flexible loads in the microgrid. This adjusts the active power command in the outer loop of the flexible load converter, reducing the active power flowing out of the microgrid and thus improving the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0035] The second approach involves adjusting the outer-loop active power command of the grid-connected converter of the energy storage device based on its adjustable capacity, thereby injecting energy into the microgrid and thus improving the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0036] The third option is to simultaneously adjust the power commands of the flexible load converter and the energy storage converter with adjustable capacity, so that the instantaneous energy balance index value of the microgrid is restored to the upper and lower limits when the microgrid is working normally.

[0037] If the above conditions are not met, proceed to the next step.

[0038] As a preferred embodiment of the microgrid instantaneous energy hierarchical control method of the present invention, the step of determining whether a large disturbance or fault has occurred in the microgrid includes:

[0039] Determine the instantaneous energy balance index value of the microgrid Less than the minimum allowable value during normal operation Or greater than the maximum limit allowed during normal operation. This indicates that the instantaneous energy of the microgrid system is seriously deviating from the balance value, and at the same time, the DC voltage of the converter is also seriously deviating from the rated value, and the microgrid needs to be shut down immediately.

[0040] Simultaneously, based on the time-series data of DC-side voltage and power of each converter, the instantaneous energy balance index value of the microgrid caused by fluctuations can be quickly located. Identify faulty converters with abnormally low or high voltage levels, and simultaneously determine if a fault has occurred in the microgrid.

[0041] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of a microgrid instantaneous energy hierarchical control method.

[0042] A computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of a microgrid instantaneous energy hierarchical control method.

[0043] The beneficial effects of this invention are as follows: By calculating the instantaneous energy balance index value of the microgrid, this invention can conveniently determine the instantaneous energy balance state of the microgrid system; at the same time, by setting graded limits for the instantaneous energy balance index of the microgrid, it helps to restore the instantaneous energy balance of the microgrid through the adjustment of the outer loop power command of the flexible load or energy storage device converter, thereby improving the transient stability of the microgrid.

[0044] Based on the magnitude of the microgrid's instantaneous energy balance index, it is possible to quickly determine whether a large disturbance or AC / DC fault has occurred in the microgrid system. At the same time, based on the DC-side power and DC voltage of each converter, it is possible to quickly determine which converter caused the instantaneous energy imbalance in the system and the possible fault type. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of a microgrid instantaneous energy hierarchical control method according to an embodiment of the present invention.

[0047] Figure 2 This is a schematic diagram of a three-phase AC microgrid structure containing multiple grid-connected converters, which provides a microgrid instantaneous energy hierarchical control method according to an embodiment of the present invention.

[0048] Figure 3 A simplified diagram of the inner and outer loop vector control structure of a grid-connected converter for a microgrid instantaneous energy hierarchical regulation method provided in one embodiment of the present invention. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0050] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0051] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0052] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0053] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0054] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] Example 1, referring to Figures 1-3This is the first embodiment of the present invention, which provides a method for instantaneous energy hierarchical control of a microgrid, comprising:

[0056] S1: Collect multi-component seabed node data and preprocess the data.

[0057] The step of setting tiered limits for the instantaneous energy balance index of the microgrid includes obtaining the rated DC voltage and capacitance values ​​of all converters in the microgrid. Assuming there are n converters in the microgrid, the rated DC voltage of the k-th converter is... The DC side capacitor value is where k = 1, 2, ..., n;

[0058] Assume the voltage on the DC side of the k-th converter in the microgrid is... Then the instantaneous energy per unit value of the k-th converter Calculate using the following formula:

[0059]

[0060] The instantaneous energy balance index of the microgrid is set as the weighted average of the instantaneous energy on the DC side of all converters in the microgrid. The weighting factor for the instantaneous energy of each converter is: The instantaneous energy balance index of the microgrid The mathematical expression is as follows:

[0061]

[0062] Set microgrid instantaneous energy balance index The tiered limits, the instantaneous energy balance index of microgrids The tiered limits include those for microgrids during normal operation. The upper and lower limits are respectively , and during normal working hours The maximum and minimum allowed values ​​are respectively , .

[0063] Microgrid instantaneous energy balance index The relationship between the four limits is as follows: < < < ;

[0064] Regarding the selection of graded limits for the microgrids involved, the instantaneous energy balance index of the microgrid under different operating conditions is calculated or simulated. The values ​​are based on the instantaneous energy balance index of the microgrid calculated and simulated under different operating conditions. Values ​​are used to determine the instantaneous energy balance index of the microgrid. The numerical values ​​of the four limits.

[0065] S2: Real-time detection of DC-side voltage and current values ​​of all converters in the microgrid, and calculation of the instantaneous energy balance index value of the microgrid.

[0066] The calculation of the instantaneous energy balance index value of the microgrid includes real-time detection and acquisition of the DC-side voltage and current values ​​of all converters in the involved microgrid, where the DC-side voltage value of the k-th converter in the microgrid is... The current value is ;

[0067] Calculate the instantaneous energy balance index of the microgrid based on the DC-side voltage values ​​of each converter in the microgrid. value;

[0068] Based on the DC-side voltage value of the k-th converter in the microgrid Current value Calculate the DC-side power of the k-th converter. ,Right now ,pass The sign of the value determines the direction of energy inflow and outflow within the k-th converter.

[0069] Obtain the DC-side power of the converter connected to the flexible load in the microgrid, and determine the adjustable capacity of the flexible load based on the current power and capacity of the flexible load;

[0070] The state of charge (SOC) of the batteries in the energy storage device in the microgrid and the DC-side power of the converter connected to the energy storage device are obtained, and the available adjustable capacity of the energy storage battery is determined based on the SOC value of the energy storage device.

[0071] Determine the instantaneous energy balance index value of the microgrid Are the upper and lower limits during normal operation? , Between, that is ≤ ≤ If the condition is met, return to the previous step; otherwise, proceed to the next step.

[0072] If the instantaneous energy balance index value of the microgrid Upper and lower limits during normal operation , If the conditions are not met, no additional adjustment is needed to the power command of the microgrid converter; otherwise, proceed to the next step.

[0073] Determine the instantaneous energy balance index value of the microgrid Is it less than the maximum limit allowed during normal operation? ,Right now The values ​​satisfy the following relationship < < ;

[0074] If the instantaneous energy balance index value of the microgrid is less than the maximum allowable limit value during normal operation... and greater than If so, the priority is to restore the instantaneous energy balance of the microgrid by adjusting the power command of the converter connected to the flexible load, and then consider restoring the instantaneous energy balance of the microgrid by adjusting the power command of the converter of the energy storage device. There are three operation schemes for restoring the instantaneous energy balance of the microgrid.

[0075] The first approach is to select a flexible load converter with adjustable capacity based on the adjustable capacity of the flexible load in the microgrid, adjust the active power command of the outer loop of the flexible load converter, increase the active power value flowing out of the microgrid, and restore the instantaneous energy balance index value of the microgrid to between the upper and lower limits when the microgrid is working normally.

[0076] The second approach involves adjusting the outer-loop active power command of the energy storage device's converter based on its adjustable capacity, enabling the energy storage device to absorb excess energy from the microgrid. In this case, the microgrid's instantaneous energy balance index value... Return to the upper and lower limits that are in normal operation of the microgrid;

[0077] The third approach involves adjusting the power commands of flexible load converters and energy storage converters with adjustable capacity to adjust the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0078] If the above conditions are not met, proceed to the next step.

[0079] S3: Determine whether the instantaneous energy balance index value of the microgrid exceeds the limit.

[0080] Determining the instantaneous energy per unit value of a microgrid Is it greater than the minimum allowable value during normal operation? ,Right now The value range satisfies the following relationship < < ;

[0081] If the instantaneous energy balance index value of the microgrid Greater than the minimum allowable value during normal operation ,Right now The values ​​satisfy the following relationship < < If so, the priority is to restore the instantaneous energy balance of the microgrid by adjusting the power command of the flexible load grid-connected converter, and then consider restoring the instantaneous energy balance of the microgrid by adjusting the power command of the energy storage device converter. There are three operation schemes for restoring the instantaneous energy balance of the microgrid.

[0082] The first approach involves selecting a flexible load converter with adjustable capacity based on the adjustable capacity of the flexible loads in the microgrid. This adjusts the active power command in the outer loop of the flexible load converter, reducing the active power flowing out of the microgrid and thus improving the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0083] The second approach involves adjusting the outer-loop active power command of the grid-connected converter of the energy storage device based on its adjustable capacity, thereby injecting energy into the microgrid and thus improving the instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0084] The third approach considers simultaneously adjusting the power commands of flexible load converters and energy storage converters with adjustable capacity to achieve the desired instantaneous energy balance index of the microgrid. Return to the upper and lower limits that are in normal operation of the microgrid;

[0085] If the above conditions are not met, proceed to the next step.

[0086] S4: If a large disturbance or fault is determined to have occurred in the microgrid, the microgrid will be shut down.

[0087] The determination that a large disturbance or fault has occurred in the microgrid includes...

[0088] The instantaneous energy balance index value of the microgrid is determined to be less than the minimum allowable value during normal operation. Or greater than the maximum limit allowed during normal operation. This indicates that the instantaneous energy of the microgrid system is seriously deviating from the balance value, and at the same time, the DC voltage of the converter is also seriously deviating from the rated value, and the microgrid needs to be shut down immediately.

[0089] Simultaneously, based on the time-series data of DC-side voltage and power of each converter, the instantaneous energy balance index value of the microgrid caused by fluctuations can be quickly located. Identify faulty converters with abnormally low or high voltage levels, and simultaneously determine if a fault has occurred in the microgrid.

[0090] Example 2

[0091] The second embodiment of the present invention differs from the first embodiment in that:

[0092] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0093] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0094] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0095] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0096] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0097] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A microgrid transient energy hierarchical regulation method, characterized in that: Comprising, setting a hierarchical limit of a micro-grid transient energy balance index; real-time detecting the DC side voltage and current value of all converters in the micro-grid, and calculating the micro-grid transient energy balance index value; judging whether the micro-grid transient energy balance index value, the micro-grid transient energy balance index value, and the micro-grid transient energy balance index value exceed the limit; if it is determined that a large disturbance or fault occurs in the micro-grid, the micro-grid is shut down.

2. The microgrid transient energy hierarchical regulation method of claim 1, wherein: The grading limit value of the setting micro-grid transient energy balance index comprises: acquiring all DC side rated voltage values and capacitance values of all converters in the micro-grid involved; assuming that there are n converters in the micro-grid, the DC side rated voltage of the kth converter is , and the DC side capacitance value is , wherein k=1, 2, …n. Assume that the voltage value of the DC side of the kth converter in the microgrid is The instantaneous energy unit value of the kth converter is calculated by the following formula: The micro-grid instantaneous energy balance index is set as the weighted average value of the instantaneous energy of all DC sides of the micro-grid converter Wherein the weighted coefficient of each converter instantaneous energy is The mathematical expression of the micro-grid instantaneous energy balance index is as follows: Setting hierarchical limit of micro-grid transient energy balance index Setting hierarchical limit of micro-grid transient energy balance index The upper and lower limit values of the micro-grid transient energy balance index during normal operation of the micro-grid are , respectively, and the maximum and minimum limit values allowed during normal operation of the micro-grid are , , respectively.

3. The microgrid transient energy hierarchical regulation method of claim 2, wherein: The grading limit value of the micro-grid transient energy balance index includes four limit values of the micro-grid transient energy balance index The size relationship of the four limit values is as follows: ;​​​ Regarding the selection of graded limits for the microgrids involved, the instantaneous energy balance index of the microgrid under different operating conditions is calculated or simulated. The values ​​are based on the instantaneous energy balance index of the microgrid calculated and simulated under different operating conditions. Values ​​are used to determine the instantaneous energy balance index of the microgrid. The numerical values ​​of the four limits.

4. The microgrid transient energy hierarchical regulation method of claim 3, wherein: The calculating micro-grid instantaneous energy balance index value comprises: detecting and acquiring the DC side voltage and current value of all converters in the micro-grid in real time, the DC side voltage value of the kth converter in the micro-grid is , and the current value is . According to the voltage values of the DC sides of the various converters in the microgrid, the instantaneous energy balance index of the microgrid is calculated values; According to the DC side voltage value of the kth converter in the microgrid , the current value , the DC side power of the kth converter is calculated , that is , the positive and negative of , the internal energy inflow and outflow direction of the kth converter is judged; obtaining the DC side power of the converter connected to the flexible load in the micro-grid, and determining the adjustable capacity of the flexible load according to the current power and capacity of the flexible load; obtaining the state of charge of the battery in the energy storage device in the micro-grid and the DC side power of the converter connected to the energy storage device, and determining the available adjustable capacity of the energy storage battery according to the SOC value of the energy storage device.

5. The microgrid transient energy hierarchical regulation method of claim 4, wherein: The judgment of whether the micro-grid transient energy balance index value, the micro-grid transient energy balance index value, and the micro-grid transient energy balance index value exceed the limit comprises, Determine the micro-grid transient energy balance index value Whether the upper and lower limit values during normal operation , , that is ≤ ≤ , if satisfied, return to the previous step, if not satisfied, enter the next step. If the micro-grid transient energy balance index value is between the upper and lower limit values in normal operation , , no additional adjustment of the power command of the micro-grid converter is required, if not, the next step is entered.

6. The microgrid transient energy hierarchical regulation method of claim 5, wherein: The judging micro-grid transient energy balance index value, micro-grid transient energy balance index value, judging whether the transient energy balance index value of the micro-grid exceeds the limit includes judging whether the micro-grid transient energy balance index value is less than the maximum limit value allowed during normal operation , that is The value satisfies the following relationship ;​​ If the micro-grid transient energy balance index value is less than the maximum limit value allowed during normal operation , and greater than , then the micro-grid transient energy balance is restored by prioritizing adjustment of the power command of the converter coupled to the flexible load, then by adjusting the power command of the converter coupled to the energy storage device, and then by adjusting the power command of the converter coupled to the energy storage device, for a total of three operating scenarios. The first scheme is to select the flexible load converter with adjustable capacity according to the adjustable capacity of the flexible load in the micro-grid, adjust the outer ring active power instruction of the flexible load converter, increase the active power value flowing out of the micro-grid, and make the instantaneous energy balance index value of the micro-grid restore to the upper and lower limit values when the micro-grid is normally working. The second scheme is to adjust the outer loop active power instruction of the energy storage device converter according to the adjustable capacity of the energy storage device, so that the energy storage device absorbs the surplus energy in the micro-grid, at this time the micro-grid instantaneous energy balance index value restores between the upper and lower limit values when the micro-grid is normally working. The third scheme is to adjust the power instruction of the flexible load converter and the energy storage converter with adjustable capacity, so that the micro-grid instantaneous energy balance index value is restored between the upper and lower limit values when the micro-grid is normally working. if the above conditions are not met, the next operation step is performed.

7. The microgrid transient energy hierarchical regulation method of claim 6, wherein: The judging micro-grid transient energy balance index value, micro-grid transient energy balance index value, judging whether the transient energy index value of the micro-grid exceeds the limit includes judging whether the transient energy index value of the micro-grid is greater than the minimum limit allowed during normal operation , i.e. , i.e. The value range satisfies the following relationship , , ; If the micro-grid transient energy balance index value is greater than the minimum limit value allowed during normal operation That is The value satisfies the following relationship If the micro-grid transient energy balance index valueThen, the power instruction of the grid-connected converter of the flexible load is adjusted to restore the micro-grid transient energy balance, and the power instruction of the converter of the energy storage device is adjusted to restore the micro-grid transient energy balance, and the three operation schemes for restoring the micro-grid transient energy balance are considered.​ The first scheme is to select the flexible load converter with adjustable capacity according to the adjustable capacity of the flexible load in the micro-grid, adjust the outer loop active power instruction of the flexible load converter, reduce the active power value flowing out of the micro-grid, and make the micro-grid instantaneous energy balance index value restore between the upper and lower limit values when the micro-grid is normally working. The second scheme is to adjust the outer loop active power instruction of the energy storage device grid-connected converter according to the adjustable capacity of the energy storage device, so that the energy storage device injects energy into the micro-grid, thereby making the micro-grid instantaneous energy balance index value restore to the upper and lower limit values when the micro-grid is normally working; The third scheme is to consider simultaneously adjusting the power instruction of the flexible load converter and the energy storage converter with adjustable capacity, so that the micro-grid instantaneous energy balance index value restores between the upper and lower limit values when the micro-grid is normally working. if the above conditions are not met, the next step is entered.

8. The microgrid transient energy hierarchical regulation method of claim 7, wherein: The determination of whether a large disturbance or fault occurs in the micro-grid comprises, Determining a microgrid transient energy balance index value less than a minimum limit value allowed during normal operation , or greater than a maximum limit value allowed during normal operation , indicating that the transient energy of the microgrid system deviates from the balance value, and the DC voltage of the converter also deviates from the rated value, and the microgrid needs to be shut down immediately Meanwhile, according to the time sequence data of the DC side voltage and power of each converter, the fluctuation causing the transient energy balance index value of the microgrid is quickly located The fault converter with abnormally low or high voltage is determined, and whether the microgrid has a fault is determined. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the method of any one of claims 1 to 8.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 8.

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