Voltage capacity formatting method of energy storage system

Abstract

The invention discloses a voltage capacity formatting method of an energy storage system, and relates to the field of energy storage of new energy power systems. In order to solve the problem of unbalanced battery voltage capacity in the existing energy storage system, after any battery is connected to the n-parallel m-series battery energy storage system, the battery energy storage system judges the battery voltage capacity difference in the parallel connection direction and the battery module voltage capacity difference in the series connection direction; according to whether the voltage capacity difference exceeds a preset threshold parameter or not, parallel reconfiguration, series reconfiguration or series-parallel reconfiguration is started, the battery energy storage system carries out battery equalization, and the voltage capacity difference of the battery is eliminated; and module-level current equalization is realized by executing the series reconfiguration, the parallel reconfiguration or the series-parallel reconfiguration. The method and the device are mainly used for carrying out voltage capacity formatting on any battery connected into the energy storage system.

Description

Technical Field

[0001] This invention relates to the field of energy storage in new energy power systems, and in particular to a voltage capacity formatting method for energy storage systems. Background Technology

[0002] Traditional energy storage systems have strict requirements for battery voltage and capacity consistency at each stage of installation, commissioning, and operation. During the installation and commissioning phase, the initial battery capacity must be consistent to meet the system's commissioning requirements. This places strict requirements on the consistency of voltage and capacity of incoming batteries, increasing management costs. During the system operation phase, if a battery fails and needs to be replaced, the replacement battery must have the same capacity as the original battery in the system. This operation is time-consuming, labor-intensive, and inefficient.

[0003] Therefore, there is a need for a voltage and capacity formatting method for energy storage systems that can reduce the requirements for the initial consistency of the connected batteries, improve the operating efficiency of the battery energy storage system, and enhance the ease of maintenance. Summary of the Invention

[0004] In order to solve the problem of unbalanced battery voltage and capacity in existing energy storage systems, this invention provides a voltage and capacity formatting method for energy storage systems that can reduce the requirements for the consistency of the initial state of connected batteries, improve the operating efficiency of battery energy storage systems, and facilitate maintenance.

[0005] The voltage capacity formatting method for an energy storage system according to the present invention includes: After any battery is connected to a battery energy storage system with n parallel and m series connections, the battery energy storage system determines the voltage-capacity difference between the batteries in the parallel direction and the voltage-capacity difference between the battery modules in the series direction. If the voltage-capacity difference exceeds the first preset threshold parameter, parallel reconfiguration is enabled, and the battery energy storage system performs battery balancing in the parallel direction to eliminate the battery voltage-capacity difference in the parallel direction. If the voltage-capacity difference exceeds the second preset threshold parameter, series reconfiguration is enabled, and the battery energy storage system performs battery balancing in the series direction to eliminate the battery voltage-capacity difference in the series direction. If the voltage capacity difference in both the parallel and series directions of the battery exceeds the corresponding preset threshold, then a series-parallel reconfiguration is performed. The battery energy storage system simultaneously balances the batteries in both the parallel and series directions to eliminate the voltage capacity difference between the batteries in the series and parallel directions. Module-level current balancing is achieved by performing the series reconfiguration, parallel reconfiguration, or series-parallel reconfiguration.

[0006] Furthermore: the battery energy storage system includes a digital energy network card, a digital energy switch, a digital energy hub, and a digital energy adapter; The digital energy network card is used to collect battery voltage and capacity data in real time and to connect or disconnect the battery module. The digital energy switch is used to process the voltage capacity data and generate a balancing strategy; The digital energy hub is responsible for coordinating communication between various modules and executing balancing strategies. The digital energy adapter is used to improve balancing efficiency and reduce energy loss. In case of an abnormality, it protects the battery system by cutting off the power circuit.

[0007] Furthermore: the specific steps of the parallel reconfiguration are as follows: S11. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S12. The battery energy storage system automatically selects the battery with the highest voltage and capacity in the same parallel battery pack to connect to the system, isolates the battery with the lowest voltage and capacity, and disconnects it from the system; and completes the issuance of operating status commands for all batteries in the system. S13. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S14. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of each battery in the same parallel battery pack are equal. If they are not equal, continue to execute S12-S13. If they are equal, execute S15. S15. Set the discharge power to zero and end the formatting operation.

[0008] Furthermore: In each parallel battery pack, a dynamic reconfiguration action n is performed on the n batteries, where x ≤ n and x > 0; when n > 1, the battery energy storage system is reconfigured in the parallel direction, thereby eliminating the voltage capacity difference between each battery module in the current parallel battery pack.

[0009] Furthermore, the specific steps of the series reconstruction are as follows: S21. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S22. The battery energy storage system automatically selects the parallel battery pack with the highest voltage capacity to connect to the system, and isolates the parallel battery pack with the lowest voltage capacity from the system. S23. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S24. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of different parallel battery groups are equal. If they are not equal, continue to execute S22-S23. If they are equal, proceed to S25. S25. Set the discharge power to zero and end the formatting operation.

[0010] Furthermore: Taking the parallel battery pack as a unit, a dynamic reconfiguration action m is performed in the series direction, where y≤m and y>0; when m>1, the battery energy storage system is reconfigured in the series direction, thereby eliminating the voltage capacity difference between different parallel battery modules.

[0011] Furthermore: the specific steps of the series-parallel reconfiguration are as follows: S31. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S32, The battery energy storage system's formatted series-parallel reconfiguration strategy is executed: both series reconfiguration and parallel reconfiguration are executed simultaneously; S33. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S34. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of different parallel battery groups are equal and whether the voltage and capacity of each battery in the same parallel battery group are equal. If there is an unequal situation, continue to execute S32-S33. If they are all balanced, proceed to S35. S35. Set the discharge power to zero and end the formatting operation.

[0012] Furthermore, the difference between the reconfiguration process during charging and the reconfiguration process during discharging is that the reconfiguration process during charging disconnects the battery with the highest voltage capacity from the system.

[0013] The beneficial effects of this invention are: This invention is used to format the voltage and capacity of batteries in an energy storage system. It supports the mixing of battery modules with arbitrary initial capacities, and after capacity formatting, achieves the goal of consistent capacity for all battery modules. It is also applicable to battery replacement operations during operation. When a battery replacement operation is required, it is not necessary to consider whether the capacity of the replaced battery is consistent with the original system battery; the replacement can be performed directly. After the replacement, a voltage and capacity formatting operation is performed once to achieve the goal of consistent voltage and capacity for all battery modules.

[0014] This invention significantly reduces the consistency requirements of the battery's initial state through an intelligent dynamic reconfiguration strategy, while simultaneously improving system operating efficiency and maintenance convenience. In practical applications, this method not only reduces the workload during installation and commissioning but also optimizes the battery management process during system operation. Furthermore, through real-time monitoring and equalization of battery status, the overall lifespan of the battery pack can be extended, and the risk of performance degradation due to battery imbalance can be reduced. This method provides a novel technical path for the efficient operation and maintenance of energy storage systems, possessing broad application prospects and practical value. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a battery energy storage system; Figure 2 This is a flowchart of parallel reconfiguration; Figure 3 This is a flowchart of the serial reconstruction process; Figure 4 This is a flowchart of serial-parallel reconfiguration; Figure 5 It is a system current curve; Figure 6 This is a graph showing the maximum and minimum values ​​of the system pack voltage; Figure 7 This is the voltage diagram for all packs. Detailed Implementation

[0016] The following are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The embodiments described below are only for explaining the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention should be determined by the scope of the claims. The embodiments of the present invention are described in detail below. In order to facilitate the description of the present invention and simplify the description, the technical terms used in the specification of the present invention should be interpreted broadly, including but not limited to conventional alternatives not mentioned in this application, and including both direct and indirect implementation methods.

[0017] Example 1 Combination Figure 1 and Figure 2 This embodiment discloses a voltage capacity formatting method for an energy storage system. Any battery energy storage system consists of multiple batteries with a topology of n parallel and m series, where n≥1 and m≥1, including various series-parallel combinations. A schematic diagram is shown below. Figure 1 As shown.

[0018] A battery energy storage system is a software-defined dynamic topology energy exchange system based on energy information technology. The battery energy storage system includes a digital energy network interface card (NIC), a digital energy switch, a digital energy hub, and a digital energy adapter. The digital energy network card is used to collect battery voltage and capacity data in real time and to connect or disconnect the battery module. The digital energy switch is used to process the voltage and capacity data, generate a balancing strategy, and adjust the balancing strategy according to the specific characteristics of the battery. The digital energy hub is responsible for coordinating communication between various modules and executing balancing strategies. The digital energy adapter is used to improve balancing efficiency and reduce energy loss. In case of an anomaly, it can quickly cut off the power circuit at the microsecond level to protect the battery system.

[0019] During operation, battery energy storage systems can isolate one or more battery modules in real time as needed. When a battery fails, the faulty battery is quickly isolated to ensure the safety of the system's batteries. When battery imbalance occurs, batteries can be temporarily isolated depending on their specific conditions, and then reconnected to the system when conditions are met, thus achieving battery balancing.

[0020] The action of a battery energy storage system controlling the connection and disconnection of a battery as needed is called battery reconfiguration; the battery connection and disconnection actions performed in real time during operation are called dynamic reconfiguration of the battery energy storage system.

[0021] According to the battery network topology, dynamic reconfiguration of battery energy storage systems can be divided into parallel dynamic reconfiguration and series dynamic reconfiguration.

[0022] For a battery energy storage system with n parallel and m series connections, there are n batteries in the parallel direction, which form a parallel battery pack; and m batteries in the series direction, which form a parallel battery pack.

[0023] Parallel-direction dynamic reconfiguration refers to the dynamic reconfiguration action n selected by x for each of the n batteries in a parallel battery pack, where x ≤ n and x > 0. When n > 1, the battery energy storage system can reconfigure in the parallel direction, which can eliminate the voltage difference of this parallel battery pack and make the voltage difference between each battery module in this parallel battery pack more balanced.

[0024] Series-direction dynamic reconfiguration refers to performing a dynamic reconfiguration action m-y in the series direction on a unit basis, where y≤m and y>0. When m>1, the battery energy storage system can be reconfigured in the series direction, which can eliminate the voltage difference between different parallel battery modules.

[0025] After any battery is connected to a battery energy storage system with n parallel and m series connections, the system determines the voltage-capacity difference between the batteries in the parallel direction. If the voltage-capacity difference exceeds a first preset threshold parameter, parallel reconfiguration is activated to balance the batteries in the parallel direction and eliminate the voltage-capacity difference. At the same time, the system determines the voltage-capacity difference between the battery modules in the series direction. If the voltage-capacity difference exceeds a second preset threshold parameter, series reconfiguration is activated to eliminate the voltage-capacity difference in the series direction. If there are voltage-capacity differences between the batteries in both the parallel and series directions, parallel reconfiguration and series reconfiguration can be performed simultaneously, which is called series-parallel reconfiguration.

[0026] By performing the above series reconfiguration, parallel reconfiguration, and series-parallel reconfiguration, module-level current balancing can be achieved. The balancing time is short and the operating efficiency is high. This can make the voltage and capacity of the m*n battery modules in the entire battery energy storage system more balanced, achieving the effect of battery voltage and capacity formatting.

[0027] Parallel reconfiguration: If the voltage and capacity of a parallel battery pack are unbalanced, parallel reconfiguration can be performed. It supports parallel reconfiguration of one parallel battery pack, as well as multiple or all parallel battery packs.

[0028] Batteries are connected in parallel via a digital energy network card, supporting microsecond-level connection and disconnection of battery modules. In a parallel battery pack, if a battery needs to be connected to the system, it is connected to the battery energy storage system under the control of the digital energy network card; if a battery does not need to be connected to the system, it is disconnected from the system under the control of the network card, also known as bypassing. If the entire parallel group does not need to be connected to the system, it can be completely disconnected from the system under the control of the network card, and all batteries are bypassed.

[0029] This function can meet the needs of various application scenarios. In normal operation mode, all parallel batteries can be selected; in case of a faulty battery, the faulty battery energy storage system can continue to operate to ensure system safety; when there is an imbalance in parallel batteries, parallel reconstruction can be enabled to balance the batteries; and the capacity can be expanded quickly without changing the voltage level, and new battery modules can be directly connected in parallel without adjusting the system voltage adapter components.

[0030] The following example of unbalanced parallel batteries will be used to explain the parallel reconfiguration process in detail.

[0031] For example, in a 3p14s battery energy storage system, n=3, m=14s. The first parallel group has three batteries: 1p1s, 1p2s, and 1p3s, with voltages of 53.2V, 53.3V, and 51.2V respectively. These three batteries have unbalanced voltages. During system operation, the battery voltages are collected, and parallel reconfiguration is performed. If the system is discharging, the battery with the highest voltage and capacity within the same parallel group is connected to the system, while the battery with the lowest voltage and capacity is isolated and disconnected from the system. If the system is charging, the battery with the lowest voltage and capacity is connected to the system, while the battery with the highest voltage and capacity is isolated and disconnected from the system. The batteries are then formatted to ensure consistent voltage and capacity. The following describes the execution steps using discharging as an example: S11. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S12. System formatting parallel reconfiguration strategy execution: The battery energy storage system automatically selects the battery with the highest voltage and capacity in the same parallel battery pack to connect to the system, isolates the battery with the lowest voltage and capacity, and disconnects it from the system; completes the issuance of operating status instructions for all batteries in the system; Taking the above 3p14s battery energy storage system as an example, select two batteries, 1p1s and 1p2s, to connect to the battery energy storage system, and isolate the 1p3s battery; other parallel battery packs are selected in the same way; complete the issuance of operating status commands for all batteries in the system.

[0032] S13. The battery energy storage system monitors the battery status and the battery energy storage system status in real time to ensure system safety.

[0033] S14. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of each battery in the same parallel battery pack are equal. If they are not equal, continue to execute S12-S13. If they are equal, execute S15. The detection frequency can be set to real-time detection or to detect at a preset time interval. S15. Set the discharge power to zero and end the formatting operation.

[0034] Series reconfiguration is achieved by connecting batteries in series via a digital energy network card, supporting microsecond-level access and disconnection of battery modules. Batteries are first connected in parallel, then in series. If none of the parallel batteries need to be connected to the system, they can all be disconnected from the system and bypassed under the control of the network card. This step is the foundation of series reconfiguration.

[0035] This function can meet the needs of various application scenarios. In normal operation mode, all series batteries can be selected; in case of a faulty battery, the faulty battery energy storage system can continue to operate to ensure system safety; when there is an imbalance in series batteries, series reconstruction can be activated to balance the batteries; the output voltage can be flexibly adjusted by increasing or decreasing the number of series modules to accurately match the load voltage requirements.

[0036] If the voltages of different parallel battery packs in a battery energy storage system are unbalanced, a series reconfiguration can be performed. The following section takes the unbalanced series batteries as an example to explain the series reconfiguration process in detail.

[0037] For example, in a 3p14s series-parallel system, n=3, m=14s. The first parallel group has 3 batteries: 1p1s, 1p2s, and 1p3s, with voltages of 53.2V, 53.3V, and 53.1V respectively, and an average voltage of 53.2V. The second parallel group has 3 batteries: 2p1s, 2p2s, and 2p3s, with voltages of 53.3V, 53.2V, and 53.1V respectively, and an average voltage of 53.2V. The third parallel group has 3 batteries: 3p1s, 3p2s, and 3p3s, with voltages of 51.2V, 51.3V, and 51.1V respectively, and an average voltage of 51.2V. ... Because the average voltage difference between the third parallel battery group and the other parallel battery groups is 2V, the battery voltages in this system are unbalanced in the series direction.

[0038] During system operation, battery voltage is collected, and series reconfiguration is performed. If the system is discharging, the parallel battery pack with the highest voltage and capacity is connected to the system, while the parallel battery pack with the lowest voltage and capacity is isolated and disconnected from the system. If the system is charging, the parallel battery pack with a lower voltage and capacity is connected to the system, while the parallel battery pack with the highest voltage and capacity is isolated and disconnected from the system. The batteries are then formatted to ensure consistent voltage and capacity. The following describes the execution steps using discharging as an example: S21. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S22. System formatted series reconfiguration strategy execution: The battery energy storage system automatically selects the parallel battery pack with the highest voltage capacity to connect to the system, and isolates the parallel battery pack with the lowest voltage capacity from the system. Taking the aforementioned 3p14s battery energy storage system as an example, the third parallel battery pack is isolated, and the remaining parallel battery packs are selected to connect to the battery energy storage system; the operating status commands for all batteries in the system are issued, and the 14-to-13 selection in the series direction is executed. For example, in a 3p14S system where parallel connections are followed by series connections, three batteries are connected in parallel as a parallel group, and there are 14 such parallel groups connected in series. The so-called 14-to-13 selection means selecting 13 parallel groups that meet the conditions to operate, and disconnecting the other parallel group that does not meet the conditions.

[0039] S23. The battery energy storage system monitors the battery status and system status in real time to ensure system safety.

[0040] S24. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of different parallel battery groups are equal. If they are not equal, continue to execute S22-S23; if they are equal, proceed to S25. The detection frequency can be set to real-time detection or to detection at preset time intervals. S25, power set to zero, system shutdown, formatting operation complete.

[0041] Series-parallel reconfiguration is achieved by connecting batteries in series and parallel via a digital energy network card, supporting microsecond-level access and disconnection of battery modules. In a parallel battery pack, if a battery needs to be connected to the system, it is connected under the control of the network card; if a battery does not need to be connected to the system, it is disconnected from the system under the control of the network card, also known as bypassing. If the entire parallel group does not need to be connected to the system, it can be completely disconnected from the system under the control of the network card, resulting in complete bypassing.

[0042] This function can meet the needs of various application scenarios. In normal operation mode, all batteries are selected. If a single battery fails, the system quickly bypasses the faulty battery, allowing continued operation and ensuring system safety. If the entire parallel battery group fails, the system quickly bypasses the faulty battery in the parallel group, allowing continued operation and ensuring system safety, with strong system redundancy. When there is an imbalance between series and parallel batteries, series-parallel reconstruction is activated to balance the batteries. It takes into account both voltage regulation and capacity expansion, and can be used for both series boost and parallel expansion to adapt to various load specifications. It can adapt to complex operating conditions and can dynamically adjust the series and parallel topology according to the load power and voltage requirements to optimize energy utilization efficiency.

[0043] If a battery energy storage system has voltage and capacity imbalances between different parallel battery packs, as well as voltage and capacity imbalances within the same parallel battery pack, a series-parallel reconfiguration can be performed. The parallel reconfiguration process is described in detail below.

[0044] For example, in a 3p14s system, n=3, m=14s. The first parallel group has three batteries: 1p1s, 1p2s, and 1p3s, with voltages of 53.2V, 53.3V, and 51.2V respectively, and an average voltage of 52.5V. The second parallel group has three batteries: 2p1s, 2p2s, and 2p3s, with voltages of 53.3V, 53.2V, and 53.1V respectively, and an average voltage of 53.2V. The third parallel group has three batteries: 3p1s, 3p2s, and 3p3s, with voltages of 51.2V, 51.3V, and 51.1V respectively, and an average voltage of 51.2V; ... Because the average voltage difference between the third parallel battery group and the other parallel battery groups is 2V, the battery voltage in this system is unbalanced in the series direction. Similarly, because the three batteries in the first parallel battery group also have a voltage difference of approximately 2V, the battery voltage in this system is also unbalanced in the parallel direction. To improve efficiency, series reconfiguration and parallel reconfiguration can be performed simultaneously.

[0045] During system operation, battery voltage is collected, and series-parallel reconfiguration is performed.

[0046] Parallel connection direction: If in discharge mode, select the battery with the highest voltage and capacity in the same parallel group to connect to the system, and isolate the battery with the lowest voltage and capacity from the system. If in charging mode, select the battery with a lower voltage and capacity to connect to the system, and isolate the battery with the highest voltage and capacity from the system. Format the batteries to make their voltage and capacity consistent.

[0047] Series connection direction: If in discharge mode, select the parallel battery pack with the highest voltage and capacity to connect to the system, and isolate the parallel battery pack with the lowest voltage and capacity from the system. If in charging mode, select the parallel battery pack with the lower voltage and capacity to connect to the system, and isolate the parallel battery pack with the highest voltage and capacity from the system. Format the batteries to make their voltage and capacity consistent.

[0048] The execution steps are described using discharge as an example: S31. Enter formatting and reconstruction mode, configure the system for discharge mode. Power on, set discharge power, and begin discharging.

[0049] S32. System formatted serial-parallel reconfiguration strategy execution: Series direction: Automatically selects the parallel battery pack with the highest voltage and capacity to connect to the system, isolates the parallel battery pack with the lowest voltage and capacity, and disconnects it from the system; isolates the third parallel battery pack, selects the remaining parallel battery packs to connect to the battery energy storage system; completes the issuance of operating status commands for all batteries in the system, and executes the 14-to-13 series direction.

[0050] Parallel connection direction: Automatically select the battery with the highest voltage and capacity to connect to the system, and isolate the battery with the lowest voltage and capacity from the system; select two batteries, 1p1s and 1p2s, to connect to the battery energy storage system, and isolate the 1p3s battery; other parallel battery packs are selected in the same way; S33. The system monitors the battery status and battery energy storage system status in real time. S34. During the system discharge process, the voltage and capacity of each battery are detected in real time (or at certain time intervals) to determine whether the voltage and capacity of different parallel battery groups are equal (balanced) and whether the voltage and capacity of each battery in the same parallel battery group are equal (balanced). If they are not equal, continue to execute S32-S34. If they are all equal, proceed to S35. S35, power set to zero, system shutdown, formatting operation complete.

[0051] The test verification is as follows: The test environment was a battery energy storage system with 1 parallel and 8 series connections; The specifications of the lithium iron phosphate battery cell are: 3.2V / 314AH; The specifications of the lithium iron phosphate battery module are: 70.4V / 314AH The test content is as follows: 1. Create a pressure difference, and the voltage after settling is (75.27V, 73.65V, 73.22V, 73.63V, 73.64V, 73.60V, 73.63V, 73.56V); 2. Serial reconfiguration mode, 20kW discharge power; 3. After serial reconstruction is complete, the voltages (73.29, 73.35, 73.09, 73.37, 73.39, 73.33, 73.37, 73.29) have been settling. 4. Disconnect auxiliary power.

[0052] The test data is as follows: The system current curve is shown below. Figure 5 As shown in the figure, the maximum and minimum values ​​of the system pack voltage are plotted as follows. Figure 6 As shown, the voltage diagrams of all packs in the system are as follows: Figure 7 As shown.

[0053] Test conclusion: Under a 2V voltage difference, the system underwent series reconfiguration for approximately 4 hours, reducing the voltage difference to around 0.3V. Based on this data, the system can perform series reconfiguration under high current conditions at the cell level, quickly balancing the battery voltage difference and improving operational efficiency.

Claims

1. A voltage capacity formatting method for an energy storage system, characterized in that, include: After any battery is connected to a battery energy storage system with n parallel and m series connections, the battery energy storage system determines the voltage-capacity difference between the batteries in the parallel direction and the voltage-capacity difference between the battery modules in the series direction. If the voltage-capacity difference exceeds the first preset threshold parameter, parallel reconfiguration is enabled, and the battery energy storage system performs battery balancing in the parallel direction to eliminate the battery voltage-capacity difference in the parallel direction. If the voltage-capacity difference exceeds the second preset threshold parameter, series reconfiguration is enabled, and the battery energy storage system performs battery balancing in the series direction to eliminate the battery voltage-capacity difference in the series direction. If the voltage capacity difference in both the parallel and series directions of the battery exceeds the corresponding preset threshold, then a series-parallel reconfiguration is performed. The battery energy storage system simultaneously balances the batteries in both the parallel and series directions to eliminate the voltage capacity difference between the batteries in the series and parallel directions. Module-level current balancing is achieved by performing the series reconfiguration, parallel reconfiguration, or series-parallel reconfiguration.

2. The voltage capacity formatting method for an energy storage system according to claim 1, characterized in that, The battery energy storage system includes a digital energy network card, a digital energy switch, a digital energy hub, and a digital energy adapter; The digital energy network card is used to collect battery voltage and capacity data in real time and to connect or disconnect the battery module. The digital energy switch is used to process the voltage capacity data and generate a balancing strategy; The digital energy hub is responsible for coordinating communication between various modules and executing balancing strategies. The digital energy adapter is used to improve balancing efficiency and reduce energy loss. In case of an abnormality, it protects the battery system by cutting off the power circuit.

3. The voltage capacity formatting method for an energy storage system according to claim 2, characterized in that, The specific steps of the parallel reconfiguration are as follows: S11. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S12. The battery energy storage system automatically selects the battery with the highest voltage and capacity in the same parallel battery pack to connect to the system, and isolates the battery with the lowest voltage and capacity from the system. Complete the issuance of commands regarding the operating status of all system batteries; S13. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S14. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of each battery in the same parallel battery pack are equal. If they are not equal, continue to execute S12-S13. If they are equal, execute S15. S15. Set the discharge power to zero and end the formatting operation.

4. The voltage capacity formatting method for an energy storage system according to claim 3, characterized in that, In each parallel battery pack, a dynamic reconfiguration action n is performed on the n batteries, where x ≤ n and x > 0. When n > 1, the battery energy storage system is reconfigured in the parallel direction, thereby eliminating the voltage capacity difference between each battery module in the current parallel battery pack.

5. The voltage capacity formatting method for an energy storage system according to claim 2, characterized in that, The specific steps of the series reconstruction are as follows: S21. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S22. The battery energy storage system automatically selects the parallel battery pack with the highest voltage capacity to connect to the system, and isolates the parallel battery pack with the lowest voltage capacity from the system. S23. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S24. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of different parallel battery groups are equal. If they are not equal, continue to execute S22-S23. If they are equal, proceed to S25. S25. Set the discharge power to zero and end the formatting operation.

6. The voltage capacity formatting method for an energy storage system according to claim 5, characterized in that, The system performs a dynamic reconfiguration action m selects y in the series direction, with each parallel battery pack as a unit, where y ≤ m and y > 0; when m > 1, the battery energy storage system is reconfigured in the series direction, thereby eliminating the voltage capacity difference between different parallel battery modules.

7. The voltage capacity formatting method for an energy storage system according to claim 2, characterized in that, The specific steps of the series-parallel reconfiguration are as follows: S31. Enter the formatting and reconfiguration mode. The battery energy storage system sets the discharge power and begins discharging. S32, The battery energy storage system's formatted series-parallel reconfiguration strategy is executed: both series reconfiguration and parallel reconfiguration are executed simultaneously; S33. The battery energy storage system monitors the battery status and the battery energy storage system status in real time. S34. During the discharge process of the battery energy storage system, the voltage and capacity of each battery are detected to determine whether the voltage and capacity of different parallel battery groups are equal and whether the voltage and capacity of each battery in the same parallel battery group are equal. If there is an unequal situation, continue to execute S32-S33. If they are all balanced, proceed to S35. S35. Set the discharge power to zero and end the formatting operation.

8. A voltage capacity formatting method for an energy storage system according to any one of claims 1-7, characterized in that, The difference between the reconfiguration process during charging and the reconfiguration process during discharging is that the reconfiguration process during charging disconnects the battery with the highest voltage capacity from the system.

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