Network construction type energy storage cooperative control method and system suitable for wide-area isolated network

Abstract

The invention provides a network construction type energy storage cooperative control method and system suitable for a wide-area isolated network, and the method comprises the steps: recognizing a range entering the wide-area isolated network based on the voltage of a tie line point and the state of a circuit breaker, and recognizing the network construction type energy storage distribution in the wide-area isolated network; detecting a connection line between the network construction type energy storage based on a path search method; judging whether each micro-grid has a tie line with other micro-grids or not within the wide-area isolated network range, and if yes, supporting the voltage and frequency stability of the micro-grids through the tie lines; if not, constructing an isolated micro-grid for maintaining the balance of the electric power and the electric quantity of the micro-grid; therefore, wide-area isolated network construction type energy storage cooperative operation is realized. According to the method, the micro-grid is taken as an entry point, the internal stability of the micro-grid is realized, the problem of local isolated grid operation is solved, cooperation and mutual assistance among the micro-grids can be considered, constraint conditions such as loss are comprehensively considered, and the stability of a wide-area alternating-current power grid is maintained.

Description

Technical Field

[0001] The present invention relates to a network-building type energy storage collaborative control method and system applicable to wide-area isolated networks, belonging to the technical field of new energy power transmission. Background Art

[0002] In recent years, with the increasing energy crisis and environmental degradation, the development of renewable energy such as wind power and photovoltaics has attracted more and more attention. However, these renewable energy sources have inherent intermittent and volatile characteristics, which have brought certain negative impacts on the stable operation and reliable power supply of the power system. The energy storage system can effectively solve the technical problems of volatility and randomness of the new energy system. The energy storage system can not only stabilize the new energy but also operate in an isolated network. The energy storage system with a grid-forming function can generate a variable voltage and frequency as a voltage source in the system. However, within the scope of a wide-area isolated network, multiple grid-forming energy storages are used as voltage source points at the same time, and they need to cooperate to realize the control of the isolated network flow to solve the operation problem of the isolated network within a wide area. However, there is currently no research on the cooperation between energy storages in the state of a wide-area isolated network to establish a free and controllable flow, and it cannot be applied to the entire isolated network.

[0003] CN118017592A discloses a method for coordinating frequency-stabilized uninterrupted energy storage power supply points under large fluctuation conditions of isolated grid. By establishing a system voltage / frequency dynamic characteristic analysis model, it reveals the mechanism of the grid-type energy storage system supporting the voltage / frequency stability of small hydropower units, provides theoretical support for the capacity configuration of energy storage systems and grid-type converters, and integrates the general grid-type control technology of multi-control function energy storage converters. It adopts DC-coupled energy storage grid-connected topology, and uses multiple strings of distributed energy storage on the DC side to access the DC bus through a bidirectional DC-DC converter. It uses the power electronic power supply of the energy storage converter and relies on the current source type virtual synchronous control algorithm to achieve active support. This patent is a control method for realizing fluctuations in isolated grids, and does not analyze the stable system. It is mainly aimed at energy storage and small hydropower, and is not applicable to the entire isolated grid.

[0004] CN119051088A discloses a method for controlling an isolated water storage microgrid with delayed energy storage control, comprising the following steps: S1, according to the energy storage device controller in the water storage microgrid, through the frequency data detection of the grid-connected switch valve of the water storage microgrid or the energy storage device controller, determine whether it is in an isolated state, if so, execute step S2; S2, according to the preset first time interval T, obtain the real-time current frequency of the isolated water storage grid, and calculate the frequency change according to the real-time current frequency; S3, according to the frequency change, control the energy storage device controller to adjust the frequency. This patent is a frequency adjustment method for energy storage and small hydropower, and does not analyze the stable system. It is only for energy storage and small hydropower, and is not applicable to the entire isolated grid.

[0005] CN111817322A discloses a load balancing method and device based on energy storage and reactive power compensation system in an isolated grid, the method includes: when the load of the isolated grid system suddenly increases, the reactive power and active power required by the isolated grid system are compensated by the reactive power compensation system and the energy storage system; when the load of the isolated grid system suddenly decreases, the reactive power and active power of the isolated grid system are absorbed by the reactive power compensation system and the energy storage system. This patent is a voltage amplitude adjustment method for realizing energy storage and reactive power supplement devices, and does not analyze the stable system. It only targets between energy storage and reactive power supplement devices, and is not applicable to the entire isolated grid. Summary of the invention

[0006] In order to solve the shortcomings of the prior art that the stable system cannot be analyzed and cannot be applied to the entire isolated grid, the present invention provides a grid-forming energy storage collaborative control method and system applicable to a wide-area isolated grid.

[0007] The present invention adopts the following technical solution.

[0008] On one hand, the present invention discloses a network-building type energy storage collaborative control method applicable to a wide-area isolated network, comprising:

[0009] Based on the tie line point voltage and circuit breaker status, the scope of entry into the wide-area isolated grid is identified, and the grid-type energy storage distribution within the wide-area isolated grid is identified;

[0010] Detect the connection lines between grid-type energy storage based on the path search method;

[0011] In the wide-area isolated network, it is determined whether each microgrid has a connecting line with other microgrids. If not, an isolated microgrid is constructed to maintain the power balance of the microgrid; if so, the voltage and frequency stability of the microgrid are supported by the connecting line, thereby realizing the coordinated operation of wide-area isolated network-type energy storage.

[0012] More preferably,

[0013] The scope of entering the wide area isolated network is identified based on the tie line point voltage and the circuit breaker state, that is, when the grid connection point voltage is less than the set voltage threshold and the interruption point and the fixed contact of the circuit breaker opening device are separated, it is judged that the wide area power grid has entered the isolated network state.

[0014] More preferably,

[0015] The ratio of the set voltage threshold to the rated voltage of the grid connection point is 0.6.

[0016] More preferably,

[0017] The details of supporting the voltage and frequency stability of the microgrid through the tie line are as follows:

[0018] Divide the isolated grid into multiple microgrids;

[0019] Aggregate the grid-connected energy storage support capabilities of each microgrid, as well as the capacity of loads and new energy;

[0020] Determine whether the grid-type energy storage and new energy capacity in each microgrid are matched. If not, re-divide the regional microgrid; if so, further determine whether the grid-type energy storage, new energy generation and load capacity in each microgrid are matched;

[0021] If it is determined that there is a mismatch between the grid-type energy storage, new energy generation and load capacity within the microgrid, the regional microgrid will be re-divided; if it is determined that the grid-type energy storage and load capacity within each microgrid are matched, the main power supply of each microgrid will be planned and power will be supplied to the isolated grid;

[0022] When the microgrid AC voltage amplitude deviation is greater than the first voltage deviation threshold, and the microgrid frequency deviation is greater than the first frequency deviation threshold, search for a microgrid that can cooperate in the isolated grid; otherwise, re-plan the main power supply of the microgrid;

[0023] The startup instructions are distributed to each grid-type energy storage, and the voltage and frequency stability of each microgrid is supported through the interconnection lines.

[0024] More preferably,

[0025] The method for judging whether the capacity of grid-connected energy storage and new energy in a certain microgrid matches is as follows: the ratio of the total capacity of all energy storage charging and discharging in the microgrid to the total capacity of new energy power generation equipment is calculated. When the calculated ratio is less than the set capacity ratio threshold, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid matches; otherwise, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid does not match.

[0026] More preferably,

[0027] When the grid-type energy storage, renewable energy generation and load capacity in a microgrid satisfy the following formula, it is determined that the grid-type energy storage, renewable energy generation and load capacity in the microgrid match, otherwise they do not match:

[0028] 0.9≤C M ≤1.1;

[0029] Among them, C M As shown below:

[0030]

[0031] Among them, α is the weight coefficient of the charging and discharging capacity of the grid-type energy storage in the microgrid; C E is the total charging and discharging capacity of the grid-type energy storage in the microgrid; β is the weight coefficient of the renewable energy generation capacity in the microgrid; C Nis the total capacity of renewable energy generation in the microgrid; P L is the total power value required by the load in the microgrid.

[0032] More preferably,

[0033] The main power source for each microgrid is to use the most important grid-connected energy storage in each microgrid as the main power source;

[0034] The importance of each type of energy storage in each microgrid is calculated according to the following formula:

[0035]

[0036] Where h is an integer and h∈[1,N Z ],N Z is the total number of microgrids in the isolated grid; i is an integer, and i∈[1,N E,h ],N E,h is the total number of grid-connected energy storage in the hth microgrid; j is an integer, and j∈[1,N E,h ];IM E,h,i is the importance of the i-th grid-connected energy storage in the h-th microgrid; C E,h,i is the charging and discharging capacity of the i-th grid-type energy storage in the h-th microgrid; S h,i is the charge state of the i-th grid-connected energy storage in the h-th microgrid; S h,j is the state of charge of the jth grid-connected energy storage in the hth microgrid; γ h,i,k The importance coefficient of the i-th grid-connected energy storage in the h-th microgrid when the main power supply of each microgrid is planned for the k-th time; k = 1, 2, ...

[0037] More preferably,

[0038] When the main power supply of each microgrid is determined for the k+1th time, the importance coefficient γ of the i-th grid-connected energy storage in the h-th microgrid h,i,k+1 As shown below:

[0039]

[0040] Wherein, ζ is the importance change coefficient, and its preferred value range is 0.1-0.4; St h,i is the i-th grid-connected energy storage in the h-th microgrid.

[0041] More preferably,

[0042] The construction method of the isolated microgrid is as follows:

[0043] Based on the microgrid coordination controller, the grid-connected energy storage in the microgrid is aggregated to support the grid, as well as the capacity of loads and new energy sources;

[0044] Determine whether the grid-type energy storage and new energy capacity in the microgrid match. If not, re-aggregate the support capacity of the grid-type energy storage in the microgrid to the grid until it is determined that the grid-type energy storage and new energy capacity in the microgrid match. The construction of the isolated microgrid is completed, and the constructed isolated microgrid is used to maintain the power balance of the microgrid.

[0045] On the other hand, the present invention discloses a network-type energy storage cooperative control system suitable for wide-area isolated networks based on a network-type energy storage cooperative control method suitable for wide-area isolated networks, including an isolated network range and energy storage distribution identification module, a network-type energy storage interconnection line detection module, an interconnection line discrimination module between microgrids, a first cooperative operation realization module and a second cooperative operation realization module:

[0046] The isolated network range and energy storage distribution identification module identifies the range of entering the wide area isolated network based on the tie line point voltage and circuit breaker status, and identifies the network type energy storage distribution in the wide area isolated network;

[0047] The interconnection line detection module between the network-forming energy storages detects the interconnection lines between the network-forming energy storages based on a path search method;

[0048] The interconnection line determination module between the microgrids determines whether each microgrid has interconnection lines with other microgrids within the wide-area isolated network. If not, it switches to the first module for collaborative operation implementation; if yes, it switches to the second module for collaborative operation implementation;

[0049] The simultaneous operation realizes the first module; constructs an isolated microgrid for maintaining the power balance of the microgrid;

[0050] The collaborative operation implements the second module, supporting the stability of the microgrid voltage and frequency through the interconnection line, thereby realizing the collaborative operation of wide-area isolated grid-type energy storage.

[0051] On the other hand, the present application discloses an electronic device, including a processor and a storage medium; the characteristics are:

[0052] The storage medium is used to store instructions;

[0053] The processor is used to operate according to the instructions to execute the aforementioned grid-type energy storage collaborative control method applicable to wide-area isolated grids.

[0054] The present application also discloses a computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method for coordinated control of networked energy storage applicable to wide-area isolated networks is implemented.

[0055] The beneficial effects of the present invention are as follows:

[0056] When operating in an isolated grid, the microgrid is used as the entry point. At the same time, it not only achieves stability within the microgrid and solves the problem of local isolated grid operation, but also adjusts the operating status of the equipment in the microgrid in real time based on the real-time changes in the operating status of the AC grid, grid-type energy storage, new energy power generation equipment and loads, and the equipment's own capabilities. At the same time, the synergy between microgrids is considered, and constraints such as losses are comprehensively considered to maintain the stability of the wide-area AC grid.

[0057] In summary, the present invention can be applied to the entire isolated grid while analyzing the stable system. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a flow chart of a grid-building energy storage collaborative control method applicable to wide-area isolated grids;

[0059] Figure 2 It is a schematic diagram of a wide area isolated network system. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0061] This application discloses a network-building energy storage collaborative control method applicable to wide-area isolated grids, see Attachment Figure 1 ,include:

[0062] Based on the tie line point voltage and circuit breaker status, the scope of entry into the wide-area isolated grid is identified, and the grid-type energy storage distribution within the wide-area isolated grid is identified;

[0063] The scope of entering the wide area isolated network is identified based on the tie line point voltage and the circuit breaker state, that is, when the grid connection point voltage is less than the set voltage threshold, and the disconnection point and the fixed contact of the circuit breaker opening device are separated, it is judged that the wide area power grid enters the isolated network state. The ratio of the set voltage threshold to the rated voltage of the grid connection point is 0.6.

[0064] Detect the connection lines between grid-type energy storage based on the path search method;

[0065] In the wide-area isolated network, it is determined whether each microgrid has a connecting line with other microgrids. If not, an isolated microgrid is constructed to maintain the power balance of the microgrid; if so, the voltage and frequency stability of the microgrid are supported by the connecting line, thereby realizing the coordinated operation of wide-area isolated network-type energy storage.

[0066] The details of supporting the voltage and frequency stability of the microgrid through the tie line are as follows:

[0067] Divide the isolated grid into multiple microgrids;

[0068] Aggregate the grid-connected energy storage support capabilities of each microgrid, as well as the capacity of loads and new energy;

[0069] Determine whether the grid-type energy storage and new energy capacity in each microgrid are matched. If not, re-divide the regional microgrid; if so, further determine whether the grid-type energy storage, new energy generation and load capacity in each microgrid are matched;

[0070] The method for judging whether the capacity of grid-connected energy storage and new energy in a certain microgrid matches is as follows: the ratio of the total capacity of all energy storage charging and discharging in the microgrid to the total capacity of new energy power generation equipment is calculated. When the calculated ratio is less than the set capacity ratio threshold, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid matches; otherwise, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid does not match.

[0071] When the grid-type energy storage, renewable energy generation and load capacity in a microgrid satisfy the following formula, it is determined that the grid-type energy storage, renewable energy generation and load capacity in the microgrid match, otherwise they do not match:

[0072] 0.9≤C M ≤1.1;

[0073] Among them, C M As shown below:

[0074]

[0075] Among them, α is the weight coefficient of the charging and discharging capacity of the grid-type energy storage in the microgrid; C E is the total charging and discharging capacity of the grid-type energy storage in the microgrid; β is the weight coefficient of the renewable energy generation capacity in the microgrid; C N is the total capacity of renewable energy generation in the microgrid; P L is the total power value required by the load in the microgrid.

[0076] If it is determined that there is a mismatch between the grid-type energy storage, new energy generation and load capacity within the microgrid, the regional microgrid will be re-divided; if it is determined that the grid-type energy storage and load capacity within each microgrid are matched, the main power supply of each microgrid will be planned and power will be supplied to the isolated grid;

[0077] The main power source for each microgrid is to use the most important grid-connected energy storage in each microgrid as the main power source;

[0078] The importance of each type of energy storage in each microgrid is calculated according to the following formula:

[0079]

[0080] Where h is an integer and h∈[1,N Z ],N Z is the total number of microgrids in the isolated grid; i is an integer, and i∈[1,N E,h ],N E,h is the total number of grid-connected energy storage in the hth microgrid; j is an integer, and j∈[1,N E,h ];IM E,h,i is the importance of the i-th grid-connected energy storage in the h-th microgrid; C E,h,i is the charging and discharging capacity of the i-th grid-type energy storage in the h-th microgrid; S h,i is the charge state of the i-th grid-connected energy storage in the h-th microgrid; S h,j is the state of charge of the jth grid-connected energy storage in the hth microgrid; γ h,i,k The importance coefficient of the i-th grid-connected energy storage in the h-th microgrid when the main power supply of each microgrid is planned for the k-th time; k = 1, 2, ...

[0081] When the main power supply of each microgrid is determined for the k+1th time, the importance coefficient γ of the i-th grid-connected energy storage in the h-th microgrid h,i,k+1 As shown below:

[0082]

[0083] Wherein, ζ is the importance change coefficient, and its preferred value range is 0.1-0.4; St h,i is the i-th grid-connected energy storage in the h-th microgrid.

[0084] When the microgrid AC voltage amplitude deviation is greater than the first voltage deviation threshold, and the microgrid frequency deviation is greater than the first frequency deviation threshold, search for a microgrid that can cooperate in the isolated grid; otherwise, re-plan the main power supply of the microgrid;

[0085] The startup instructions are distributed to each grid-type energy storage, and the voltage and frequency stability of each microgrid is supported through the interconnection lines.

[0086] The construction method of the isolated microgrid is as follows:

[0087] Based on the microgrid coordination controller, the grid-connected energy storage in the microgrid is aggregated to support the grid, as well as the capacity of loads and new energy sources;

[0088] Determine whether the grid-type energy storage and new energy capacity in the microgrid match. If not, re-aggregate the support capacity of the grid-type energy storage in the microgrid to the grid until it is determined that the grid-type energy storage and new energy capacity in the microgrid match. The construction of the isolated microgrid is completed, and the constructed isolated microgrid is used to maintain the power balance of the microgrid.

[0089] Example 1

[0090] The present application discloses a network-building energy storage collaborative control method applicable to a wide-area isolated grid, see Attachment Figure 1 ,include:

[0091] Step 1: Based on the tie line point voltage and circuit breaker status, identify the scope of entry into the wide-area isolated grid, and then identify the grid-type energy storage distribution within the wide-area isolated grid;

[0092] The identification of the scope of entering the wide area isolated network based on the tie line point voltage and circuit breaker status is to detect the tie line connection point voltage and circuit breaker status between the region and the AC large power grid through the wide area coordinated controller to determine whether the wide area power grid has entered the isolated network state; when the connection point voltage is less than the set voltage threshold and the disconnection point and fixed contact in the circuit breaker opening device are separated, it is determined that the wide area power grid has entered the isolated network state. Preferably, the set voltage threshold is 0.6 pu of the rated voltage of the connection point, that is, the ratio of the set voltage threshold to the rated voltage is 0.6.

[0093] The identification of the distribution of the grid-forming energy storage in the wide-area isolated network is to determine whether there is available grid-forming energy storage in the area through the wide-area regional collaborative controller, and further identify the distribution status and geographical location of the grid-forming energy storage in the area through the wide-area regional collaborative controller on the basis of the available grid-forming energy storage;

[0094] Step 2: Detect the connection lines between the grid-type energy storages based on the path search method;

[0095] The path search method is used to detect the communication lines between the grid-type energy storage. Specifically, the path search method detects the electrical nodes where the grid-type energy storage is located through the wide area collaborative controller and connects the grid-type energy storage through the communication lines to construct an electrical topology diagram with the grid-type energy storage as the core.

[0096] Detect whether the communication lines between the grid-type energy storage are available, and construct the communication method between the grid-type energy storage with the shortest path. If one grid-type energy storage cannot establish a connection with other grid-type energy storage through the communication line, then this grid-type energy storage is isolated from the wide-area isolated network and enters the microgrid mode. The grid-type energy storage is isolated from the wide-area isolated network and enters the microgrid mode, that is, the grid-type energy storage cannot enter the wide-area isolated network, and can only establish a regional microgrid with the grid-type energy storage as the core, such as a village microgrid. The grid-type energy storage can only maintain the operation of the regional microgrid and cannot provide support for other power grid systems.

[0097] Step 3: Determine whether each microgrid within the wide-area isolated network has a connection line with other microgrids within the wide-area isolated network. If so, the connection line is used to support the stability of the microgrid voltage and frequency. Figure 2If not, an isolated microgrid is constructed to maintain the power balance of the microgrid, as shown in Figure 2 As shown in the microgrid 5, the wide-area isolated grid-type energy storage coordinated operation can be realized;

[0098] The determination of whether each microgrid within the wide-area isolated network has a connection line with other microgrids within the wide-area isolated network is achieved by detecting through a path search method whether the two microgrids can establish an interconnected electrical channel through the connection line. Specifically, the path search method detects the electrical nodes where the grid-forming energy storage in each microgrid is located through a wide-area regional collaborative controller, and connects each electrical node through a connection line to achieve the purpose of connecting each microgrid, thereby constructing an electrical topology diagram with each microgrid as the core.

[0099] The details of supporting the voltage and frequency stability of the microgrid through the tie line are as follows:

[0100] Divide the isolated grid into N microgrids;

[0101] Those skilled in the art can divide the isolated network into N microgrids according to actual conditions; in order to improve calculation accuracy, the method of dividing the isolated network into N microgrids proposed in the embodiment of the present invention is only a preferred embodiment, and is not an inevitable limitation for implementing the collaborative control method of a grid-type energy storage applicable to a wide-area isolated network of the present invention. The isolated network is divided into N microgrids based on the principles of distance and grid-type energy storage; the specific division method is: when dividing the microgrid, fully consider the capacity constraints of new energy in the isolated island, the adjustable active and reactive power capabilities of the grid-type energy storage, and the multi-constraint conditions of the isolated island network loss to divide the microgrid;

[0102] Aggregate the support capacity of grid-connected energy storage within the microgrid to the grid, as well as the capacity of loads and new energy;

[0103] The support capability of the grid-connected energy storage within the aggregated microgrid to the power grid is to use a microgrid coordination controller to centrally and collaboratively manage the grid-connected energy storage within the microgrid, so that the grid-connected energy storage within the microgrid can orderly support the active power and reactive power of the microgrid.

[0104] Aggregating the capacity of loads and renewable energy within a microgrid refers to the centralized and coordinated management of loads and renewable energy within the microgrid through a microgrid coordination controller, achieving orderly control of loads and renewable energy within the microgrid, and jointly supporting the voltage and frequency stability of the microgrid with grid-connected energy storage.

[0105] Determine whether the grid-type energy storage and new energy capacity in each microgrid are matched. If so, further determine whether the grid-type energy storage, new energy generation and load capacity in each microgrid are matched; if not, re-divide the regional microgrid;

[0106] The determination of whether the grid-type energy storage and new energy capacity in each microgrid match is made by comparing the grid-type energy storage charging and discharging capacity with the capacity of new energy power generation equipment. If the ratio of the energy storage charging and discharging capacity to the capacity of new energy power generation equipment is less than the set capacity ratio threshold, it is determined that the grid-type energy storage and new energy capacity match, otherwise it is determined that the grid-type energy storage and new energy capacity do not match; the preferred value of the capacity ratio threshold is 0.3. The ratio of the energy storage charging and discharging capacity to the new energy power generation equipment capacity is the result of dividing the energy storage charging and discharging capacity by the capacity of new energy power generation equipment.

[0107] Those skilled in the art should know that load capacity refers to the capacity that an electrical device bears during actual use, that is, the power or energy consumed by the device in actual working state.

[0108] When the following formula is satisfied in a microgrid, it is determined that the grid-type energy storage, new energy generation and load capacity in the microgrid are matched, otherwise they are not matched:

[0109] 0.9≤C M ≤1.1;

[0110] Among them, C M As shown below:

[0111]

[0112] Among them, α is the weight coefficient of the charging and discharging capacity of the grid-type energy storage in the microgrid, and its preferred value range is 0.4-0.6; C E is the total charging and discharging capacity of the grid-type energy storage in the microgrid, that is, the sum of the charging and discharging capacities of each grid-type energy storage in the microgrid; β is the weight coefficient of the renewable energy generation capacity in the microgrid, and its selected value range is 0.4-0.6; C N is the total capacity of renewable energy generation in the microgrid, that is, the sum of the capacity of each renewable energy generation in the microgrid; P L It is the total power value of the load demand in the microgrid, that is, the sum of the power values ​​of the load demand in the microgrid.

[0113] Wherein, α is the weight coefficient of the charge and discharge capacity of the network-type energy storage, and its preferred value range is 0.4-0.6; C E is the charging and discharging capacity of the grid-type energy storage, and its selected value range is 0.4-0.6; β is the weight coefficient of the new energy power generation capacity; C N is the renewable energy power generation capacity; P L is the power value required by the load in the microgrid.

[0114] Those skilled in the art should know that renewable energy power generation capacity refers to the maximum capacity of renewable energy power generation equipment that can operate continuously within a unit time, usually in MW or GW.

[0115] Re-divide the regional microgrid, take the mismatch factors as conditions, and add corresponding equipment through the path search method, that is, add energy storage or new energy, so that the microgrid network-type energy storage, new energy power generation and load capacity match.

[0116] The re-dividing of regional microgrids is to adjust the equipment judged to be mismatched on the basis of the existing multiple microgrids; wherein the equipment includes grid-type energy storage and new energy.

[0117] When it is determined that the grid-type energy storage and the new energy capacity do not match, a new energy device adjacent to the path between the original microgrids is added through a path search method; the adjacent device refers to a device whose path length between the device and the original microgrid is less than a set first path threshold. Preferably, the first path threshold can be set to the path length from 1 to 5 new energy devices closest to the original microgrid to the original microgrid.

[0118] When it is judged that the grid-type energy storage, new energy generation and load capacity do not match, it is judged that C M Is it less than 0.9? If so, add a grid-connected energy storage or new energy device adjacent to the original microgrid through the path search method;

[0119] If not, then through the path search method, reduce a grid-connected energy storage or new energy device at the edge of the original microgrid; the edge of the microgrid refers to a position whose distance from the center point of the microgrid is greater than the set second path threshold; preferably, the second path threshold can be set to the path length from the 1 to 5 new energy devices farthest from the center point of the microgrid to the center point of the microgrid obtained by the path search method.

[0120] If it is judged that the grid-forming energy storage and load capacity in each microgrid match, the main power supply of the microgrid is planned based on the dual objectives of capacity and state of charge SOC and supplies power to the isolated grid to establish a stable isolated grid voltage and frequency; if it is judged that the grid-forming energy storage and load capacity do not match, the regional microgrid is re-divided;

[0121] The main power source for each microgrid is to use the most important grid-connected energy storage in each microgrid as the main power source;

[0122] The importance of each type of energy storage in each microgrid is calculated according to the following formula:

[0123]

[0124] Where h is an integer and h∈[1,N Z ],N Z is the total number of microgrids in the isolated grid; i is an integer, and i∈[1,N E,h ],N E,his the total number of grid-connected energy storage in the hth microgrid; j is an integer, and j∈[1,N E,h ];IM E,h,i is the importance of the i-th grid-connected energy storage in the h-th microgrid; C E,h,i is the charging and discharging capacity of the i-th grid-type energy storage in the h-th microgrid; S h,i is the charge state of the i-th grid-connected energy storage in the h-th microgrid; S h,j is the state of charge of the jth grid-connected energy storage in the hth microgrid; γ h,i,k The importance coefficient of the i-th grid-type energy storage in the h-th microgrid when the main power supply of each microgrid is planned for the kth time; k = 1, 2, ...;

[0125] The most important grid-connected energy storage in each microgrid is used as the main power supply, and other grid-connected energy storage in the microgrid is used as auxiliary power supply.

[0126] In the present invention, after the grid-type energy storage and load capacity in each microgrid are matched, the proposed microgrid main power supply is the first proposed microgrid main power supply; when setting the first proposed microgrid main power supply, the importance coefficient of each grid-type energy storage in each microgrid is 1, that is, γ is set. h,i,1 =1;γ h,i,1 Determine the importance coefficient of the i-th grid-connected energy storage in the h-th microgrid for the first time;

[0127] When it is necessary to re-plan the main power supply of a microgrid, γ h,i,k Change according to the following formula:

[0128]

[0129] Among them, γ h,i,k+1 is the importance coefficient of the i-th grid-type energy storage in the h-th microgrid when the main power supply of each microgrid is planned for the k+1th time; ζ is the importance change coefficient, and its preferred value range is 0.1-0.4; St h,i is the i-th grid-connected energy storage in the h-th microgrid.

[0130] When k is greater than 15, the loop is terminated, and the main power source obtained when the main power sources of each microgrid are proposed for the first time is used as the final main power source, and the step of searching for coordinated microgrids based on distance and support capacity is directly carried out.

[0131] Establishing stable isolated grid voltage and frequency is to establish stable grid voltage and frequency by using grid-type energy storage to control isolated grid voltage and frequency.

[0132] When the AC voltage amplitude deviation of a microgrid is greater than the first voltage deviation threshold, and the frequency deviation of the microgrid is greater than the first frequency deviation threshold, search for a microgrid that can cooperate in the isolated grid; otherwise, re-plan the main power supply of the microgrid; preferably, the first voltage threshold is set to 1kV; the first frequency threshold is set to 0.11Hz;

[0133] Among them, the microgrid AC voltage amplitude deviation is the absolute value of the difference between the actual microgrid AC voltage amplitude and the rated microgrid AC voltage amplitude; the microgrid frequency deviation is the absolute value of the difference between the actual microgrid frequency and the rated microgrid frequency;

[0134] Preferably, before searching for microgrids that can cooperate in the isolated grid, the following steps can be added:

[0135] The remaining grid-type energy storage in the microgrid is used to stabilize the voltage and frequency of the microgrid with a slope through droop control;

[0136] After the remaining grid-type energy storage in the microgrid stabilizes the voltage and frequency of the microgrid with a slope, when the microgrid AC voltage amplitude deviation is greater than the second voltage deviation threshold, and the microgrid frequency deviation is greater than the second frequency deviation threshold, search for a coordinated microgrid, otherwise the remaining grid-type energy storage in the microgrid stabilizes the voltage and frequency of the microgrid with a slope again; preferably, the first voltage threshold is set to 2kV; the first frequency threshold is set to 0.2Hz;

[0137] Those skilled in the art should know that the search for cooperative microgrids, i.e., detecting whether each microgrid has other microgrids connected to it by interconnection lines, assumes that the detected microgrid has X microgrids connected to it by interconnection lines, then these X+1 microgrids should be able to achieve voltage and frequency stability supporting X+1 microgrids through interconnection lines; those skilled in the art can search according to actual conditions; the cooperative microgrid search method proposed in the embodiment of the present invention is only a preferred embodiment, and is not an inevitable limitation for implementing the present invention's networking type energy storage cooperative control method suitable for wide-area isolated grids. The specific search method is as follows:

[0138] The search for collaborative microgrids is based on support capacity and distance. Specifically, the searched collaborative microgrid must first meet the support capacity. Secondly, the path length between the searched collaborative microgrid and the current microgrid should be as close as possible. The search for collaborative microgrids can achieve support for voltage and frequency while reducing system losses.

[0139] Further, it is assumed that the detected microgrid has X microgrids that have a tie line connection relationship with it; when X+1 microgrids meet the standby active and reactive capacity and can provide the X+1 microgrids that need to be supported through droop control calculation, it is determined that the support capacity between these X+1 microgrids is met; among the X microgrids that have a tie line connection relationship with the detected microgrid, each microgrid whose tie line length to the detected microgrid is less than a set first path length threshold is selected as a coordinated microgrid; the first path length threshold can be set to the path length from 1 to 5 new energy devices farthest from the detected microgrid in the isolated grid to the detected microgrid.

[0140] Preferably, it is determined whether there is a microgrid that provides collaborative support. If not, the relevant equipment is removed based on the cause of instability; if so, the active power and reactive power required for the stability of the microgrid are calculated based on the droop coefficient, and the instructions are distributed to the grid-forming energy storage, so as to achieve the voltage and frequency stability of the microgrid through the interconnection line. The removal of relevant equipment based on the cause of instability refers to removing equipment that makes it impossible for microgrids to achieve collaborative cooperation from the wide-area isolated network; the equipment includes loads and new energy power generation equipment;

[0141] The construction method of the isolated microgrid is as follows:

[0142] Aggregate the support capacity of grid-connected energy storage within the microgrid to the grid, as well as the capacity of loads and new energy;

[0143] Determine whether the capacity of the grid-type energy storage and new energy in the microgrid matches. If not, rebuild the grid support capacity of the grid-type energy storage in the microgrid, as well as the capacity of the load and new energy, until it is determined that the capacity of the grid-type energy storage and new energy in the microgrid matches, and the construction of the isolated microgrid is completed. The constructed isolated microgrid is used to maintain the power balance of the microgrid.

[0144] Reconstruct the grid support capabilities of the grid-connected energy storage within the microgrid, and in the process of rebuilding the capacity of the load and new energy within the microgrid, reduce constraints such as line losses, search for the required grid-connected energy storage, load and new energy equipment in a wider space, and realize the construction of the microgrid.

[0145] Example 2

[0146] A grid-connected energy storage collaborative control method suitable for wide-area isolated grids.

[0147] Step 1: The wide-area power grid system consists of multiple grid-forming energy storage, multiple grid-following energy storage, multiple new energy power generation equipment, and multiple loads. When the wide-area power grid is disconnected from the AC large power grid, it enters the isolated grid operation state. When the wide-area isolated grid is restored to power, the grid-forming energy storage is used to establish the AC voltage amplitude and frequency, and the new energy power generation equipment is connected to the isolated grid to provide power.

[0148] Step 2: See attached Figure 2 , in order to achieve the optimization and coordinated control of the wide-area isolated network, the wide-area isolated network is further subdivided into microgrids. The power dispatching in the wide-area isolated network area is realized through fast communication, so as to achieve the power balance and maintain the stability of AC voltage and frequency. The fast communication can be realized by using the standard power communication protocol of GOOSE;

[0149] Step 3: The wide area coordinated controller detects the voltage, frequency and circuit breaker status of the connection point between the area and the AC large power grid and determines whether the wide area power grid has entered an isolated grid state;

[0150] Step 4: The wide-area coordinated controller detects the available grid-forming energy storage in the area. If all grid-forming energy storage is unavailable, it is prohibited to enter the isolated grid to restore the power grid;

[0151] Step 5: After the wide-area coordinated controller detects the available grid-forming energy storage, it further identifies the distribution status and geographical location of the grid-forming energy storage in the region, and uses the path search method to detect whether the communication lines between the grid-forming energy storage are available, and constructs the communication method between the grid-forming energy storage with the shortest path. If a grid-forming energy storage cannot establish continuity with other grid-forming energy storage through the communication line, then this grid-forming energy storage is isolated from the wide-area isolated network and enters the microgrid mode.

[0152] Step 6: If the wide area collaborative controller detects that the grid-building energy storage is isolated, it will further detect the renewable energy power generation equipment and loads that need to be isolated, and further calculate whether the grid-building energy storage, renewable energy power generation equipment, and loads in the microgrid can maintain the balance of power. If not, the equipment that causes the imbalance will be removed according to the cause of the imbalance to maintain the balance of the microgrid. For example, when there are too many loads, it is necessary to remove unimportant loads and prioritize important loads into the microgrid system according to their importance. When a load requires more power, the load needs to be removed. When the reactive power required for renewable energy power generation is more, the renewable energy power generation equipment needs to be reduced.

[0153] Preferably, the formula for calculating whether the grid-type energy storage, new energy power generation equipment, and load in the microgrid can maintain the power balance is as follows:

[0154]

[0155] Among them, p(i) is the calculation result of the active power of energy storage in the microgrid + the active power of new energy - the active power of the load, and p(j) is the calculation result of the reactive power of energy storage in the microgrid + the reactive power of new energy + the reactive power of the load;

[0156] Step 7: When the wide-area regional collaborative controller detects a non-isolated microgrid, the wide-area regional collaborative controller further divides the wide-area isolated network into N microgrids based on the principle of line distance and the existence of networking type energy storage. The wide-area regional collaborative controller calculates the capacity of the aggregated networking type energy storage as the isolated grid power source point and uses the networking type energy storage with the largest capacity as the main power source point, and aggregates the SOC less than the threshold as the backup networking support power source point; wherein, when the networking type energy storage SOC is less than the threshold, it is not calculated into the capacity of the aggregated networking type energy storage. The threshold is 15%. In the present invention, aggregation and accumulation have the same meaning, that is, the wide-area regional collaborative controller calculates the capacity of the aggregated networking type energy storage, which is to calculate the sum of the capacities of all networking type energy storage in the area through the wide-area regional collaborative controller.

[0157] Step 8: The wide-area coordinated controller aggregates the load and capacity of new energy in the microgrid. The wide-area coordinated controller matches the capacity of grid-forming energy storage and new energy based on the principle of power balance in the region. If the power generation capacity of new energy satisfies the reasonable SOC of all grid-forming energy storage, that is, the SOC can be maintained within 20% to 80%, the microgrid division is reasonable, otherwise the microgrid division is re-performed;

[0158] Step 9: The wide-area coordinated controller further analyzes the capacity matching of grid-type energy storage, new energy and load based on the principle of power balance in the region. If the power generation capacity of new energy and all grid-type energy storage meet the reasonable SOC, that is, the SOC can be maintained within the threshold, and can support the load operation, then the microgrid division is reasonable, otherwise the microgrid division is re-performed;

[0159] Step 10: The wide-area regional collaborative controller starts the grid-forming energy storage to establish the microgrid AC voltage and frequency. The wide-area regional collaborative controller further starts the new energy power generation equipment and puts the microgrid load into the microgrid. Under the balance of power in the microgrid area, the grid-forming energy storage at the standby grid-forming support power source point is charged and discharged based on the principle of optimal SOC; the standby grid-forming support power source point is the grid-forming energy storage with SOC less than the threshold. The optimal SOC is the principle, that is, the SOC is maintained at 40% to 60%;

[0160] Step 11: When the wide area coordinated controller detects in real time that the grid-type energy storage at the backup grid-type supporting power source point is within the optimal SOC, it reorders the aggregated grid-type energy storage main power sources in the microgrid based on the grid-type energy storage capacity. The grid-type energy storage uses the grid-type energy storage with the largest capacity as the main control point of the isolated grid voltage. The remaining grid-type energy storage uses the voltage and frequency deviation as the target to perform auxiliary isolated grid voltage and frequency control to maintain the voltage amplitude and frequency of the microgrid within the set range.

[0161] Step 12: The wide-area regional collaborative controller takes the principle of autonomous balance within the microgrid as the main principle and collaborative complementarity between microgrid regions as the auxiliary principle. The wide-area regional collaborative controller establishes a complementary and collaborative matching mechanism for regional microgrids based on the principle of optimal path;

[0162] Step 13: The regional microgrid collaborative controller detects the AC voltage or frequency in real time. If the AC voltage or frequency deviation is greater than the set threshold, the regional microgrid collaborative controller further calculates the power balance required for the regional microgrid, that is, the increase or decrease of active and reactive power. The regional microgrid collaborative controller sends the active and reactive power instructions to the auxiliary isolated grid control network-forming energy storage, and the auxiliary isolated grid-forming energy storage adjusts the active and reactive power output to maintain the voltage and frequency stability in the microgrid;

[0163] Step 14: If the network type in the microgrid is fully charged or fully discharged, such as high frequency requires charging and low frequency requires discharging, the wide area regional collaborative controller detects the AC voltage or frequency of the interconnection line between the microgrids in real time. If the AC voltage or frequency deviation is greater than the set threshold, the wide area regional collaborative controller further calculates the power balance required for the regional microgrid, that is, the increase or decrease of active and reactive power. The wide area regional collaborative controller searches for a microgrid that can provide complementary connections through the microgrid collaborative controller. If no other microgrid can provide support, and the voltage and frequency of the microgrid are further unstable, the microgrid collaborative controller removes related equipment based on the cause of the instability. If there are too many loads, the loads are removed, and if there are too many new energy power generation equipment, the new energy power generation is reduced;

[0164] Step 15: The wide-area coordinated controller sends active and reactive power instructions to other microgrids connected to the regional microgrid based on the principle of optimal path. The microgrids adjust the active and reactive power outputs and help each other through the interconnection lines to maintain the stability of the wide-area isolated network.

[0165] The present application also discloses a network-type energy storage collaborative control system applicable to a wide-area isolated network based on a network-type energy storage collaborative control method applicable to a wide-area isolated network, including an isolated network range and energy storage distribution identification module, a network-type energy storage interconnection line detection module, an interconnection line discrimination module between microgrids, a collaborative operation realization first module and a collaborative operation realization second module:

[0166] The isolated network range and energy storage distribution identification module identifies the range of entering the wide area isolated network based on the tie line point voltage and circuit breaker status, and identifies the network type energy storage distribution in the wide area isolated network;

[0167] The interconnection line detection module between the network-forming energy storages detects the interconnection lines between the network-forming energy storages based on a path search method;

[0168] The interconnection line determination module between the microgrids determines whether each microgrid has interconnection lines with other microgrids within the wide-area isolated network. If not, it switches to the first module for collaborative operation implementation; if yes, it switches to the second module for collaborative operation implementation;

[0169] The simultaneous operation realizes the first module; constructs an isolated microgrid for maintaining the power balance of the microgrid;

[0170] The collaborative operation implements the second module, supporting the stability of the microgrid voltage and frequency through the interconnection line, thereby realizing the collaborative operation of wide-area isolated grid-type energy storage.

[0171] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0172] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0173] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0174] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be customized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A network-building energy storage collaborative control method applicable to wide-area isolated grids, characterized in that: include: Based on the tie line point voltage and circuit breaker status, the scope of entry into the wide-area isolated grid is identified, and the grid-type energy storage distribution within the wide-area isolated grid is identified; Detect the connection lines between grid-type energy storage based on the path search method; In the wide-area isolated network, it is determined whether each microgrid has a connecting line with other microgrids. If not, an isolated microgrid is constructed to maintain the power balance of the microgrid; if so, the voltage and frequency stability of the microgrid are supported by the connecting line, thereby realizing the coordinated operation of wide-area isolated network-type energy storage.

2. The grid-type energy storage collaborative control method applicable to wide-area isolated grid according to claim 1 is characterized in that: The scope of entering the wide area isolated network is identified based on the tie line point voltage and the circuit breaker state, that is, when the grid connection point voltage is less than the set voltage threshold and the interruption point and the fixed contact of the circuit breaker opening device are separated, it is judged that the wide area power grid has entered the isolated network state.

3. The grid-type energy storage collaborative control method applicable to wide-area isolated grid according to claim 2 is characterized in that: The ratio of the set voltage threshold to the rated voltage of the grid connection point is 0.

6.

4. The grid-type energy storage collaborative control method applicable to wide-area isolated grid according to claim 1 is characterized in that: The details of supporting the voltage and frequency stability of the microgrid through the tie line are as follows: Divide the isolated grid into multiple microgrids; Aggregate the grid-connected energy storage support capabilities of each microgrid, as well as the capacity of loads and new energy; Determine whether the grid-type energy storage and new energy capacity in each microgrid are matched. If not, re-divide the regional microgrid; if so, further determine whether the grid-type energy storage, new energy generation and load capacity in each microgrid are matched; If it is determined that there is a mismatch between the grid-type energy storage, new energy generation and load capacity within the microgrid, the regional microgrid will be re-divided; if it is determined that the grid-type energy storage and load capacity within each microgrid are matched, the main power supply of each microgrid will be planned and power will be supplied to the isolated grid; When the microgrid AC voltage amplitude deviation is greater than the first voltage deviation threshold, and the microgrid frequency deviation is greater than the first frequency deviation threshold, search for a microgrid that can cooperate in the isolated grid; otherwise, re-plan the main power supply of the microgrid; The startup instructions are distributed to each grid-type energy storage, and the voltage and frequency stability of each microgrid is supported through the interconnection lines.

5. The grid-connected energy storage coordinated control method applicable to wide-area isolated grid according to claim 4 is characterized in that: The method for judging whether the capacity of grid-connected energy storage and new energy in a certain microgrid matches is as follows: the ratio of the total capacity of all energy storage charging and discharging in the microgrid to the total capacity of new energy power generation equipment is calculated. When the calculated ratio is less than the set capacity ratio threshold, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid matches; otherwise, it is judged that the capacity of grid-connected energy storage and new energy in the microgrid does not match.

6. The grid-type energy storage coordinated control method applicable to wide-area isolated grid according to claim 4 is characterized in that: When the grid-type energy storage, renewable energy generation and load capacity in a microgrid satisfy the following formula, it is determined that the grid-type energy storage, renewable energy generation and load capacity in the microgrid match, otherwise they do not match: 0.9≤C M ≤1.1； Among them, C M As shown below: Among them, α is the weight coefficient of the charging and discharging capacity of the grid-type energy storage in the microgrid; C E is the total charging and discharging capacity of the grid-type energy storage in the microgrid; β is the weight coefficient of the renewable energy generation capacity in the microgrid; C N is the total capacity of renewable energy generation in the microgrid; P L is the total power value required by the load in the microgrid.

7. The grid-type energy storage coordinated control method applicable to wide-area isolated grid according to claim 4 is characterized in that: The main power source for each microgrid is to use the most important grid-connected energy storage in each microgrid as the main power source; The importance of each type of energy storage in each microgrid is calculated according to the following formula: Where h is an integer and h∈[1,N Z ],N Z is the total number of microgrids in the isolated grid; i is an integer, and i∈[1,N E,h ],N E,h is the total number of grid-connected energy storage in the hth microgrid; j is an integer, and j∈[1,N E,h ];IM E,h,i is the importance of the i-th grid-connected energy storage in the h-th microgrid; C E,h,i is the charging and discharging capacity of the i-th grid-type energy storage in the h-th microgrid; S h,i is the charge state of the i-th grid-connected energy storage in the h-th microgrid; S h,j is the state of charge of the jth grid-connected energy storage in the hth microgrid; γ h,i,k The importance coefficient of the i-th grid-connected energy storage in the h-th microgrid when the main power supply of each microgrid is planned for the k-th time; k = 1, 2, ...

8. The grid-connected energy storage coordinated control method applicable to wide-area isolated grids according to claim 4 is characterized in that: When the main power supply of each microgrid is determined for the k+1th time, the importance coefficient γ of the i-th grid-connected energy storage in the h-th microgrid h,i,k+1 As shown below: Wherein, ζ is the importance change coefficient, and its preferred value range is 0.1-0.4; St h,i is the i-th grid-connected energy storage in the h-th microgrid.

9. The grid-connected energy storage coordinated control method applicable to wide-area isolated grids according to claim 1 is characterized in that: The construction method of the isolated microgrid is as follows: Based on the microgrid coordination controller, the grid-connected energy storage in the microgrid is aggregated to support the grid, as well as the capacity of loads and new energy sources; Determine whether the grid-type energy storage and new energy capacity in the microgrid match. If not, re-aggregate the support capacity of the grid-type energy storage in the microgrid to the grid until it is determined that the grid-type energy storage and new energy capacity in the microgrid match. The construction of the isolated microgrid is completed, and the constructed isolated microgrid is used to maintain the power balance of the microgrid.

10. A networked energy storage cooperative control system applicable to a wide-area isolated network using the networked energy storage cooperative control method applicable to a wide-area isolated network as claimed in any one of claims 1 to 9, characterized in that: It includes an isolated grid range and energy storage distribution identification module, a networking type energy storage interconnection line detection module, an interconnection line identification module between microgrids, a collaborative operation realization module 1 and a collaborative operation realization module 2: The isolated network range and energy storage distribution identification module identifies the range of entering the wide area isolated network based on the tie line point voltage and circuit breaker status, and identifies the network type energy storage distribution in the wide area isolated network; The interconnection line detection module between the network-forming energy storages detects the interconnection lines between the network-forming energy storages based on a path search method; The interconnection line determination module between the microgrids determines whether each microgrid has interconnection lines with other microgrids within the wide-area isolated network. If not, it switches to the first module for collaborative operation implementation; if yes, it switches to the second module for collaborative operation implementation; The simultaneous operation realizes the first module; constructs an isolated microgrid for maintaining the power balance of the microgrid; The collaborative operation implements the second module, supporting the stability of the microgrid voltage and frequency through the interconnection line, thereby realizing the collaborative operation of wide-area isolated grid-type energy storage.

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