A battery power replenishment and balancing method and system for energy storage

Abstract

This invention proposes a battery charging and balancing method and system for energy storage. The method includes obtaining the state of charge (SOC) of the battery module and setting a SOC range. If the SOC is within the set SOC range, the abnormal cells are balanced based on the voltage of a first abnormal cell and a first normal cell of the battery module, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. If the SOC is not within the set SOC range, a first charge / discharge capacity is determined based on the voltage of a second normal cell and a cutoff voltage of the battery module, and a second charge / discharge capacity is determined based on the voltage of a second abnormal cell and a cell SOC-voltage relationship table. If the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, the abnormal cells are balanced according to the first charge / discharge capacity; otherwise, the abnormal cells are balanced according to the second charge / discharge capacity.

Description

Technical Field

[0001] This invention relates to the field of battery power replenishment and balancing technology for energy storage, and particularly to a battery power replenishment and balancing method and system for energy storage. Background Technology

[0002] In recent years, energy storage technology has seen significant development in the new energy field, especially with increasing government support for the industry. Mobile energy storage container systems are currently the primary method for constructing energy storage systems, playing a crucial economic role in wind power, solar power, and industrial peak-shifting electricity use. Their ease of transportation and installation have earned widespread industry acceptance.

[0003] However, during long-term use, energy storage containers may experience various issues, such as the voltage of the entire module or a single cell within the module exceeding or falling below the overall voltage level. This can lead to insufficient energy, excessive voltage differential alarms, and safety incidents during charging and discharging. These phenomena are caused by a bottleneck effect in a single unit and can severely impact the container's designed lifespan. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the first objective of this invention is to provide a battery replenishment and balancing method for energy storage to extend the lifespan of energy storage batteries.

[0006] The second objective of this invention is to provide a battery power replenishment and balancing system for energy storage.

[0007] The third objective of this invention is to provide an electronic device.

[0008] The fourth objective of this invention is to provide a computer-readable storage medium.

[0009] To achieve the above objectives, the first aspect of the present invention provides a battery power replenishment and balancing method for energy storage, comprising:

[0010] Obtain the state of charge (SOC) of the battery module and set the SOC range;

[0011] If the state of charge is within the set state of charge range, the abnormal cell is balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end capacities of the plateau period of the cell discharge curve.

[0012] If the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module. If the difference between the first charge / discharge capacity and the second charge / discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity.

[0013] In the method of the first aspect of the present invention, the step of balancing the abnormal cell based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end caps of the cell discharge curve, includes: determining a capacity-voltage relationship coefficient based on the start and end voltages and start and end caps of the cell discharge curve; obtaining a voltage difference based on the first abnormal cell voltage and the first normal cell voltage; obtaining a balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient; and balancing the abnormal cell based on the balanced capacity.

[0014] In the method of the first aspect of the present invention, the voltage of the first normal cell is obtained based on the average or intermediate voltage of each normal cell of the battery module.

[0015] In the method of the first aspect of the present invention, the step of determining a first charge-discharge capacity based on the second normal cell voltage and the cutoff voltage of the battery module if the state of charge is not within the set state of charge range, and determining a second charge-discharge capacity based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module, includes: if the state of charge is less than the lower limit of the set state of charge range, determining a first discharge capacity based on the second normal cell voltage and the discharge cutoff voltage of the battery module; discharging an experimental cell to the discharge cutoff voltage using constant power to obtain a cell SOC-voltage relationship table under the discharge state; and calculating the second discharge capacity based on the second abnormal cell voltage, the discharge cutoff voltage, and the cell SOC-voltage relationship table under the discharge state.

[0016] In the method of the first aspect of the present invention, the step of determining a first charge-discharge capacity based on the second normal cell voltage and the cutoff voltage of the battery module if the state of charge is not within the set state of charge range, and determining a second charge-discharge capacity based on the second abnormal cell voltage of the battery module and a cell SOC-voltage relationship table, includes: if the state of charge is greater than the upper limit of the set state of charge range, determining a first charging capacity based on the second normal cell voltage and the charging cutoff voltage of the battery module; charging an experimental cell to the charging cutoff voltage using constant power to obtain a cell SOC-voltage relationship table under charging conditions; and calculating a second charging capacity based on the second abnormal cell voltage, the charging cutoff voltage, and the cell SOC-voltage relationship table under charging conditions.

[0017] In the method of the first aspect of the present invention, the step of balancing the abnormal cell according to the first charge / discharge capacity if the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, and otherwise balancing the abnormal cell according to the second charge / discharge capacity, includes: when the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within a set discharge capacity difference range, balancing the abnormal cell according to the first discharge capacity, and otherwise balancing the abnormal cell according to the second discharge capacity; and when the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charge capacity and the second charge capacity is within a set charge capacity difference range, balancing the abnormal cell according to the first charge capacity, and otherwise balancing the abnormal cell according to the second charge capacity.

[0018] In the method of the first aspect of the present invention, the voltage of the second normal cell is obtained based on the median value of the voltage of each normal cell of the battery module.

[0019] To achieve the above objectives, a second aspect of the present invention provides a battery power replenishment and balancing system for energy storage, comprising:

[0020] The acquisition module is used to acquire the state of charge (SOC) of the battery module and set the SOC range.

[0021] The first balancing module is used to balance the abnormal cell based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end capacities of the plateau period of the cell discharge curve, if the state of charge is within the set state of charge range.

[0022] The second balancing module is used to determine a first charge / discharge capacity based on the second normal cell voltage and cutoff voltage of the battery module if the state of charge is not within the set state of charge range, and to determine a second charge / discharge capacity based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module; if the difference between the first charge / discharge capacity and the second charge / discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity.

[0023] To achieve the above objectives, a third aspect of the present invention provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory to implement the method proposed in the first aspect of the present invention.

[0024] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method proposed in the first aspect of the present invention.

[0025] The present invention provides a battery charging and balancing method, system, electronic device, and storage medium for energy storage. It acquires the state of charge (SOC) of the battery module and sets a SOC range. If the SOC is within the set range, the abnormal cells are balanced based on the voltages of the first abnormal and first normal cells, as well as the start and end voltages and capacities of the cell discharge curves. If the SOC is not within the set range, a first charge / discharge capacity is determined based on the voltages of the second normal cells and the cutoff voltage of the battery module, and a second charge / discharge capacity is determined based on the voltages of the second abnormal cells and the cell SOC-voltage relationship table. If the difference between the first and second charge / discharge capacities is within a set capacity difference range, the abnormal cells are balanced according to the first charge / discharge capacity; otherwise, they are balanced according to the second charge / discharge capacity. In this scenario, considering the state of charge (SOC) of the battery modules, different methods are used to balance battery modules with different SOC ranges. For battery modules with an SOC within the set range, abnormal cells are balanced by combining the voltage of abnormal / normal cells, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. For battery modules outside the set range, two sets of charge / discharge capacities are obtained by combining the voltage of abnormal / normal cells, the cutoff voltage, and the SOC-voltage relationship table. Then, the final charge / discharge capacity is determined by combining the set capacity difference range to balance abnormal cells. Compared to existing single charging methods, this approach can better extend the lifespan of energy storage batteries.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic flowchart of a battery power replenishment and balancing method for energy storage provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the cell discharge curve provided in an embodiment of the present invention;

[0030] Figure 3 This is a block diagram of a battery power replenishment and balancing system for energy storage provided in an embodiment of the present invention. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] The battery replenishment and balancing method and system for energy storage according to embodiments of the present invention are described below with reference to the accompanying drawings.

[0033] This invention provides a battery replenishment and balancing method for energy storage to extend the lifespan of energy storage batteries.

[0034] Figure 1 This is a schematic flowchart of a battery power replenishment and balancing method for energy storage provided in an embodiment of the present invention.

[0035] like Figure 1 As shown, the battery power replenishment and balancing method for energy storage includes the following steps:

[0036] Step S101: Obtain the state of charge (SOC) of the battery module and set the SOC range.

[0037] In step S101, the state of charge (SOC) of the battery module is obtained.

[0038] In step S101, the set state of charge (SCC) range of the battery module is also obtained. For example, if the SCC range is set to [10%, 90%], then the lower limit of the SCC range is set to 10%, and the upper limit is set to 90%.

[0039] Step S102: If the state of charge is within the set state of charge range, the abnormal cell is balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end caps of the plateau period of the cell discharge curve.

[0040] In step S102, an abnormal cell is a single cell in the battery module that is either higher or lower than other cells in the entire battery module. All other cells in the battery module are normal cells.

[0041] In step S102, for a battery module whose state of charge is within a set range, the voltage of its abnormal cell is the first abnormal cell voltage. The first normal cell voltage is obtained based on the average or median voltage of each normal cell in the battery module.

[0042] In step S102, the abnormal cells are balanced based on the voltage of the first abnormal cell and the voltage of the first normal cell in the battery module, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. This includes: determining a capacity-voltage relationship coefficient based on the start and end voltages and capacities of the plateau period of the cell discharge curve; obtaining a voltage difference based on the voltage of the first abnormal cell and the voltage of the first normal cell; obtaining a balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient; and balancing the abnormal cells based on the balanced capacity. The start and end voltages include the initial voltage and the final voltage, and the start and end capacities include the initial capacity and the final capacity.

[0043] Specifically, this will be explained using lithium iron phosphate batteries with a state of charge range of [10%, 90%].

[0044] Figure 2 This is a schematic diagram of the cell discharge curve provided in an embodiment of the present invention. Based on Figure 2 As shown in the discharge curve of the lithium iron phosphate (LFP) battery, there is a voltage plateau period during discharge. During this plateau period, the cell voltage decreases very slowly, exhibiting a linear curve. The starting voltage of the plateau period is V1, and the ending voltage is V2. The starting capacity corresponding to the starting voltage V1 is M1, and the ending capacity corresponding to the ending voltage V2 is M2. Based on the starting and ending voltages and capacities of the cell's voltage plateau period, a relationship between capacity and voltage is obtained, namely the capacity-voltage relationship coefficient N. The capacity-voltage relationship coefficient N satisfies (M2-M1) / (V1-V2)=N.

[0045] For battery modules with SOC between 10% and 90%, the voltage of the first abnormal cell, V3, is obtained under static conditions. The median value of the voltages of the other cells in the battery module, excluding the abnormal cell, is taken as the voltage of the first normal cell, V4. The voltage difference between the two is calculated, and the absolute value of the voltage difference, V, satisfies V = |V3 - V4|.

[0046] The equalization capacity, N*V, is obtained based on the voltage difference and the capacity-voltage relationship coefficient. If the voltage of the abnormal cell is lower than that of the normal cell, the abnormal cell is charged and equalized based on the equalization capacity. If the voltage of the abnormal cell is higher than that of the normal cell, the abnormal cell is discharged and equalized based on the equalization capacity. This achieves initial equalization.

[0047] In step S102, after the initial leveling, the entire battery module can be left to stand for a set time, such as more than 30 minutes, and the voltage of the abnormal cell can be measured again. This step is repeated to charge and discharge the abnormal cell until the difference between the voltage of the first abnormal cell and the voltage of the first normal cell is less than the set difference threshold (e.g., 3mV), at which point the charging action can be stopped.

[0048] Step S103: If the state of charge is not within the set state of charge range, the first charge-discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge-discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module; if the difference between the first charge-discharge capacity and the second charge-discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge-discharge capacity; otherwise, the abnormal cell is balanced according to the second charge-discharge capacity.

[0049] In step S103, for battery modules whose state of charge is not within the set state of charge range, the voltage of the abnormal cell is the second abnormal cell voltage. The second normal cell voltage is obtained based on the median value of the voltages of the normal cells in the battery module.

[0050] In step S103, if the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including:

[0051] If the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal cell voltage and the discharge cutoff voltage of the battery module; the experimental cell is discharged to the discharge cutoff voltage using constant power to obtain the cell SOC-voltage relationship table under discharge conditions; the second discharge capacity is calculated based on the second abnormal cell voltage, the discharge cutoff voltage, and the cell SOC-voltage relationship table under discharge conditions.

[0052] If the state of charge (SOC) is greater than the upper limit of the set SOC range, the first charging capacity is determined based on the second normal cell voltage and the charging cutoff voltage of the battery module; the experimental cell is charged to the charging cutoff voltage using constant power to obtain the cell SOC-voltage relationship table under charging conditions; the second charging capacity is calculated based on the second abnormal cell voltage, the charging cutoff voltage, and the cell SOC-voltage relationship table under charging conditions.

[0053] In step S103, if the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity. This includes: if the state of charge is less than the lower limit of a set state of charge range, and the difference between the first discharge capacity and the second discharge capacity is within a set discharge capacity difference range, the abnormal cell is balanced according to the first discharge capacity; otherwise, the abnormal cell is balanced according to the second discharge capacity. If the state of charge is greater than the upper limit of a set state of charge range, and the difference between the first charge capacity and the second charge capacity is within a set charge capacity difference range, the abnormal cell is balanced according to the first charge capacity; otherwise, the abnormal cell is balanced according to the second charge capacity.

[0054] Specifically, let's take a setting of the state of charge range as [10%, 90%] as an example for explanation:

[0055] If the SOC of the battery module is less than 10%, the cell voltage corresponding to the median voltage of the normal cells in the battery module is taken as the second normal cell voltage. A specific current A1 is used to discharge the cell corresponding to this second normal cell voltage until the discharge cutoff voltage, for example, 2.5V, is reached. The first discharge capacity Q1 is recorded. Then, the same specific current A1 is used to charge the cell corresponding to this second normal cell voltage according to the first discharge capacity Q1. This process is used to calibrate and confirm that the capacity range of the cells in the entire battery module is approximately around the first discharge capacity Q1. For the remaining normal and abnormal cells in the battery module, the same specific current A1 is used to discharge them until the discharge cutoff voltage, for example, 2.5V, is reached. Then, the cells are charged using the same specific current A1 according to the first discharge capacity Q1, thus achieving balancing. The cutoff condition for this balancing method is capacity, and the cutoff capacity is the first discharge capacity Q1.

[0056] If the SOC of the battery module is greater than 90%, the cell voltage corresponding to the median value of the normal cell voltage in the battery module is taken as the second normal cell voltage. A specific current A2 is used to charge the cell corresponding to this second normal cell voltage until the charging cutoff voltage, for example, 3.65V, is reached. The first charging capacity Q2 is recorded. Then, the same specific current A2 is used to discharge the cell corresponding to this second normal cell voltage according to the first charging capacity Q2. This process is used to calibrate and confirm that the capacity range of the cells in the entire battery module is approximately around the first charging capacity Q2. For the remaining normal and abnormal cells in the battery module, the same specific current A2 is used to charge them until the charging cutoff voltage, for example, 3.65V, is reached. Then, the same specific current A2 is used to discharge them according to the first charging capacity Q2, thereby achieving balancing. The cutoff condition for this balancing method is capacity, and the cutoff capacity is the first charging capacity Q2.

[0057] In some embodiments, step S103 takes into account that the first discharge capacity Q1 or the first charge capacity Q2 may not be accurate, and the second charge and discharge capacity also needs to be considered.

[0058] Specifically, taking a 280Ah battery cell as an example, the process of determining the second discharge capacity includes: discharging a single 280Ah experimental battery cell at a constant power of 0.5P under room temperature conditions of 25±2℃ until the cell discharges to the discharge cutoff voltage, for example, 2.5V, and calculating the correspondence between the cell's SOC and cell voltage (i.e., the cell SOC-voltage relationship table), as shown in Table 1. Using the cell voltage range corresponding to each SOC range in Table 1, the voltage difference in each SOC range is calculated, thereby calculating how many Ah of additional charge (CCV) is required per mV of voltage in the variable SOC range.

[0059] Table 1 Cell SOC-Voltage Relationship Table

[0060]

[0061]

[0062] Based on the data in Table 1, taking the 0%-5% range as an example, the segmentation coefficient relationship between capacity and voltage per mV is calculated as K = 280Ah * 5% / (2938.6mV - 2499.9mV) = 0.031912Ah / mV. The same method is used to calculate the segmentation coefficient relationship K for all SOC segment intervals (i.e., all ranges in Table 1).

[0063] The entire experimental battery module is discharged at a normal discharge power of 0.5P until the lowest voltage of the entire experimental battery module is reached, and then the discharge cutoff voltage, such as 2.5V, is stopped. The voltage of all cells in the experimental battery module is extracted at the moment when the discharge stops at 2.5V. The voltage of the cell that needs to be charged, V5, is obtained, and the average voltage V6 of the other normal cells in the experimental battery module is calculated. The voltage segment interval in which the voltage V5 and average voltage V6 of the cell that needs to be charged and balanced are located is found.

[0064] Taking V5 = 2703mV and V6 = 3155mV as an example, it is necessary to calculate the voltage difference of the battery cells that need to be balanced in different voltage segments. Specifically, V5 is in the 0%-5% range, and V6 is in the 15%-20% range. There are a total of 4 ranges from V5 to V6. Among them, V5 is in the 0%-5% range. The voltage difference corresponding to 2703mV-2938.6mV is denoted as V7, the voltage difference corresponding to the range of 2938.7mV-3089.3mV is denoted as V8, the voltage difference corresponding to the range of 3089.4mV-3136.4mV is denoted as V9, and the voltage difference corresponding to the range of 3136.5mV-3155mV is denoted as V10. The segment coefficient relationship K corresponding to these four ranges is calculated. For example, K1 corresponds to the 0%-5% range, K2 corresponds to the 5%-10% range, K3 corresponds to the 10%-15% range, and K4 corresponds to the 15%-20% range. Then the second discharge capacity Q3 satisfies Q3=V7*K1+V8*K2+V9*K3+V10*K10.

[0065] If the difference between the first discharge capacity Q1 and the second discharge capacity Q3 is within the set discharge capacity difference range, then the abnormal cell is balanced according to the first discharge capacity Q1; otherwise, the abnormal cell is balanced according to the second discharge capacity Q3.

[0066] In embodiments of the present invention, the second charging capacity can be obtained by analogy with the process of obtaining the second discharging capacity.

[0067] In some embodiments, if the SOC of the battery module cannot be obtained, the battery module can be balanced directly using step S103.

[0068] In some embodiments, after all the power replenishment and balancing work is completed, the battery module or system needs to undergo normal charge and discharge testing. The test should be verified by at least one complete cycle to check whether the abnormal conditions of the adjusted cells or modules have been effectively improved. If the problem disappears, it means that the power replenishment method is feasible; if the problem still exists, it means that the abnormality of a single cell or the abnormality of the entire module is not caused by capacity inconsistency, and it should be considered as a performance problem of the cell or module itself, which poses a safety hazard and requires replacement with a new cell or module for rematching.

[0069] To achieve the above embodiments, the present invention also proposes a battery power replenishment and balancing system for energy storage.

[0070] Figure 3 This is a block diagram of a battery power replenishment and balancing system for energy storage provided in an embodiment of the present invention.

[0071] like Figure 3 As shown, the energy storage battery charging and balancing system includes an acquisition module 11, a first balancing module 12, and a second balancing module 13, wherein:

[0072] The acquisition module 11 is used to acquire the state of charge of the battery module and set the state of charge range;

[0073] The first equalization module 12 is used to equalize the abnormal cell based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end caps of the plateau period of the cell discharge curve, if the state of charge is within a set state of charge range.

[0074] The second balancing module 13 is used to determine the first charge-discharge capacity based on the second normal cell voltage and cutoff voltage of the battery module if the state of charge is not within the set state of charge range, and to determine the second charge-discharge capacity based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module; if the difference between the first charge-discharge capacity and the second charge-discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge-discharge capacity, otherwise the abnormal cell is balanced according to the second charge-discharge capacity.

[0075] Furthermore, in one possible implementation of this invention, the first balancing module 12 balances the abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. This includes: determining a capacity-voltage relationship coefficient based on the start and end voltages and capacities of the plateau period of the cell discharge curve; obtaining a voltage difference based on the first abnormal cell voltage and the first normal cell voltage; obtaining a balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient; and balancing the abnormal cells based on the balanced capacity.

[0076] Furthermore, in one possible implementation of this invention, the first equalization module 12 obtains the voltage of the first normal cell based on the average or intermediate voltage of each normal cell in the battery module.

[0077] Further, in one possible implementation of this invention, in the second equalization module 13, if the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and the cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module. This includes: if the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal cell voltage and the discharge cutoff voltage of the battery module; the experimental cell is discharged to the discharge cutoff voltage using constant power to obtain the cell SOC-voltage relationship table under the discharge state; and the second discharge capacity is calculated based on the second abnormal cell voltage, the discharge cutoff voltage, and the cell SOC-voltage relationship table under the discharge state.

[0078] Further, in one possible implementation of this invention, in the second balancing module 13, if the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and the cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module. This includes: if the state of charge is greater than the upper limit of the set state of charge range, the first charging capacity is determined based on the second normal cell voltage and the charging cutoff voltage of the battery module; the experimental cell is charged to the charging cutoff voltage using constant power to obtain the cell SOC-voltage relationship table under charging conditions; and the second charging capacity is calculated based on the second abnormal cell voltage, the charging cutoff voltage, and the cell SOC-voltage relationship table under charging conditions.

[0079] Further, in one possible implementation of this invention, in the second balancing module 13, if the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, then the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity. This includes: when the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, then the abnormal cell is balanced according to the first discharge capacity; otherwise, the abnormal cell is balanced according to the second discharge capacity. When the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charging capacity and the second charging capacity is within the set charging capacity difference range, then the abnormal cell is balanced according to the first charging capacity; otherwise, the abnormal cell is balanced according to the second charging capacity.

[0080] Furthermore, in one possible implementation of this invention, the second equalization module 13 obtains the second normal cell voltage based on the median value of the voltage of each normal cell in the battery module.

[0081] It should be noted that the foregoing explanation of the embodiment of the battery replenishment and balancing method for energy storage also applies to the battery replenishment and balancing system for energy storage in this embodiment, and will not be repeated here.

[0082] In this embodiment of the invention, the state of charge (SOC) of the battery module and a set SOC range are obtained. If the SOC is within the set SOC range, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. If the SOC is not within the set SOC range, the first charge / discharge capacity is determined based on the second normal cell voltage and the cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table. If the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, the abnormal cells are balanced according to the first charge / discharge capacity; otherwise, the abnormal cells are balanced according to the second charge / discharge capacity. In this scenario, considering the state of charge (SOC) of the battery modules, different methods are used to balance battery modules with different SOC ranges. For battery modules with an SOC within the set range, abnormal cells are balanced by combining the voltage of abnormal / normal cells, as well as the start and end voltages and capacities of the plateau period of the cell discharge curve. For battery modules outside the set range, two sets of charge / discharge capacities are obtained by combining the voltage of abnormal / normal cells, the cutoff voltage, and the SOC-voltage relationship table. Then, the final charge / discharge capacity is determined by combining the set capacity difference range to balance abnormal cells. Compared to existing single charging methods, this approach can better extend the lifespan of energy storage batteries.

[0083] The method and system of this invention can complete battery charging and balancing operations faster and more scientifically. A systematic approach guides on-site after-sales personnel to perform charging and balancing according to the procedures, improving after-sales work efficiency. It reduces safety accidents that may occur during the charging and balancing process due to improper operation or data errors, while also improving product performance, reducing product safety risks, and extending product lifespan. Practical methods and data can replace previous personnel experience, and the data is traceable and scientifically sound.

[0084] To implement the above embodiments, the present invention also proposes an electronic device, including: a processor and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided in the foregoing embodiments.

[0085] To implement the above embodiments, the present invention also proposes a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the methods provided in the foregoing embodiments.

[0086] To implement the above embodiments, the present invention also proposes a computer program product, including a computer program that, when executed by a processor, implements the methods provided in the foregoing embodiments.

[0087] In the foregoing descriptions of the embodiments, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0088] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0089] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0090] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0091] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0092] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0093] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0094] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A battery power equalization method for energy storage, characterized in that, include: Obtain the state of charge (SOC) of the battery module and set the SOC range; If the state of charge is within the set state of charge range, the abnormal cell is balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end capacities of the plateau period of the cell discharge curve. If the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module. If the difference between the first charge / discharge capacity and the second charge / discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity.

2. The battery power replenishment and balancing method for energy storage according to claim 1, characterized in that, The method of balancing abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end capacities of the plateau period of the cell discharge curve, includes: The capacity-voltage relationship coefficient is determined based on the plateau period start and end voltages and start and end capacities of the cell discharge curve. The voltage difference is obtained based on the voltage of the first abnormal cell and the voltage of the first normal cell. The balanced capacity is obtained based on the voltage difference and the capacity-voltage relationship coefficient, and the abnormal cells are balanced based on the balanced capacity.

3. The battery power replenishment and balancing method for energy storage according to claim 1, characterized in that: The voltage of the first normal cell is obtained based on the average or median voltage of each normal cell in the battery module.

4. The battery power replenishment and balancing method for energy storage according to claim 1, characterized in that, If the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including: If the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal cell voltage and discharge cutoff voltage of the battery module. The experimental battery cell was discharged to the discharge cutoff voltage using constant power to obtain the SOC-voltage relationship table of the battery cell under discharge conditions; The second discharge capacity is calculated based on the second abnormal cell voltage, discharge cutoff voltage, and cell SOC-voltage relationship table under discharge conditions.

5. The battery power replenishment and balancing method for energy storage according to claim 4, characterized in that, If the state of charge is not within the set state of charge range, the first charge / discharge capacity is determined based on the second normal cell voltage and cutoff voltage of the battery module, and the second charge / discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including: If the state of charge is greater than the upper limit of the set state of charge range, the first charging capacity is determined based on the second normal cell voltage and the charging cutoff voltage of the battery module. The experimental battery cell was charged to the charging cutoff voltage using a constant power to obtain the SOC-voltage relationship table of the battery cell under charging conditions. The second charging capacity is calculated based on the second abnormal cell voltage, the charging cutoff voltage, and the cell SOC-voltage relationship table under charging conditions.

6. The battery power replenishment and balancing method for energy storage according to claim 5, characterized in that, If the difference between the first charge / discharge capacity and the second charge / discharge capacity is within a set capacity difference range, then the abnormal cells are balanced according to the first charge / discharge capacity; otherwise, the abnormal cells are balanced according to the second charge / discharge capacity. This includes: If the state of charge is less than the lower limit of the set state of charge range, and the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, then the abnormal cell is balanced according to the first discharge capacity; otherwise, the abnormal cell is balanced according to the second discharge capacity. If the state of charge is greater than the upper limit of the set state of charge range, and the difference between the first charging capacity and the second charging capacity is within the set charging capacity difference range, then the abnormal cell is balanced according to the first charging capacity; otherwise, the abnormal cell is balanced according to the second charging capacity.

7. The battery power replenishment and balancing method for energy storage according to claim 1, characterized in that: The voltage of the second normal cell is obtained based on the median value of the voltages of each normal cell in the battery module.

8. A battery power replenishment and balancing system for energy storage, characterized in that, include: The acquisition module is used to acquire the state of charge (SOC) of the battery module and set the SOC range. The first balancing module is used to balance the abnormal cell based on the first abnormal cell voltage and the first normal cell voltage of the battery module, as well as the start and end voltages and start and end capacities of the plateau period of the cell discharge curve, if the state of charge is within the set state of charge range. The second balancing module is used to determine a first charge / discharge capacity based on the second normal cell voltage and cutoff voltage of the battery module if the state of charge is not within the set state of charge range, and to determine a second charge / discharge capacity based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module; if the difference between the first charge / discharge capacity and the second charge / discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge / discharge capacity; otherwise, the abnormal cell is balanced according to the second charge / discharge capacity.

9. An electronic device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-7.

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