Battery cell detection method and device of energy storage system, energy storage system and storage medium
By setting different detection states of the cells in the energy storage system, collecting voltage information, and using the SOC-OCV curve and ampere-hour integration method, the health status of the cells can be accurately determined, solving the problem of low cell detection accuracy in the energy storage system and improving the stability and safety of the system.
Patent Information
- Application Number
- CN202511709467.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2026-02-17
AI Technical Summary
The health status detection of battery cells in energy storage systems is difficult to achieve and has low accuracy, resulting in insufficient system stability and safety.
By setting the first and second detection states, the voltage information of the battery cell is collected. Combined with the SOC-OCV curve and the ampere-hour integration method, the SOC and capacity parameters of the battery cell are determined, and then the health status is calculated.
This improves the accuracy and reliability of determining the health status of battery cells, and enhances the operational stability and safety of energy storage systems.
Smart Images
Figure CN121541085A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a cell testing method, apparatus, energy storage system, computer-readable storage medium, and computer program product for an energy storage system. Background Technology
[0002] Energy storage systems consist of multiple battery cells used to store electrical energy. Due to manufacturing tolerances, the performance of each cell may be inconsistent. Furthermore, cells age over time, reducing their capacity and health. Therefore, the capacity and health of individual cells within an energy storage system may differ, leading to a "bottleneck effect." The bottleneck effect refers to the situation where the system's shutdown condition is based on the health status of individual cells. When at least one cell prematurely reaches the shutdown condition, the entire system stops charging and discharging before other cells are fully charged or discharged. This bottleneck effect affects the stable operation of the energy storage system and poses safety hazards. Therefore, it is necessary to monitor the health status of the cells to correct their parameters. However, current technologies suffer from difficulties in detecting cell health status information, and the accuracy of the determined health status information is relatively low. Summary of the Invention
[0003] In view of the above problems, this application provides a cell testing method, device, energy storage system, computer-readable storage medium, and computer program product for an energy storage system, which can accurately determine the health status of the cells.
[0004] According to a first aspect of this disclosure, a cell detection method for an energy storage system is provided, wherein the energy storage system includes an energy storage cabinet, and multiple cells are disposed in the energy storage cabinet. The cell detection method includes: when the cell is in a first detection state, acquiring first voltage information of the cell; wherein the first detection state includes a state in which the cell is in a first static state and the static duration is greater than a first duration threshold, and in the first detection state, the state of charge (SOC) of the cell is greater than a first SOC threshold or less than a second SOC threshold, wherein the first SOC threshold is greater than the second SOC threshold; determining the first SOC of the cell based on the first voltage information of the cell; and when the cell is in a second detection state, acquiring second voltage information of the cell. Voltage information; wherein, the second detection state includes the state in which the cell is in a second static state and the static duration is greater than a second duration threshold, and in the second detection state, the SOC of the cell is less than the second SOC threshold or greater than the first SOC threshold; during the interval between the first detection state and the second detection state, the cell is controlled to perform periodic charging or periodic discharging; based on the second voltage information of the cell, the second SOC of the cell is determined; based on the first SOC, the second SOC, and the current information of the cell during the interval, the capacity parameter information of the cell is determined; based on the initial capacity information of the cell and the capacity parameter information, the health status information of the cell is determined.
[0005] In this embodiment, by setting a first detection state and a second detection state, and controlling the battery cell to charge or discharge during the interval between the first and second detection states, the accuracy of determining information such as the battery cell's health status can be ensured. Based on the battery cell's first SOC in the first detection state, the second SOC in the second detection state, and the battery cell's current information, the battery cell's capacity parameters are determined. Based on the initial capacity information and capacity parameters, the battery cell's health status information is determined. This accurately determines the battery cell's health status and other information, improving the precision and reliability of the determination. It can be used to correct the battery cell's health status parameters, thereby improving the stability and safety of the energy storage system.
[0006] In some embodiments, the first voltage information is the OCV information of the battery cell in a first detection state, and determining the first SOC of the battery cell based on the first voltage information of the battery cell includes: calculating the first SOC based on the SOC-OCV curve of the battery cell and the first voltage information.
[0007] In this embodiment, the first SOC is determined based on the SOC-OCV curve, which improves the efficiency and accuracy of the determination of the first SOC.
[0008] In some embodiments, the second voltage information is the OCV information of the battery cell in a second detection state, and determining the second SOC of the battery cell based on the second voltage information of the battery cell includes: calculating the second SOC based on the SOC-OCV curve of the battery cell and based on the second voltage information.
[0009] In this embodiment, the second SOC is determined based on the SOC-OCV curve, which improves the efficiency and accuracy of the determination of the second SOC.
[0010] In some embodiments, the battery cell is controlled to undergo periodic discharge processing during the interval time period; wherein, before the discharge processing is performed, the SOC of the battery cell is greater than the first SOC threshold, and after the discharge processing is completed, the SOC of the battery cell is less than the second SOC threshold.
[0011] In this embodiment, by controlling the battery cell to perform periodic discharge processing during the time interval between the first detection state and the second detection state, the accuracy of determining information such as the health status of the battery cell can be guaranteed.
[0012] In some embodiments, the battery cell is controlled to undergo periodic charging during the time interval; wherein, before the charging process is performed, the SOC of the battery cell is less than the second SOC threshold, and after the charging process is completed, the SOC of the battery cell is greater than the first SOC threshold.
[0013] In this embodiment, by controlling the battery cell to undergo periodic charging during the time interval between the first detection state and the second detection state, the accuracy of determining information such as the health status of the battery cell can be guaranteed.
[0014] In some embodiments, determining the capacity parameter information of the battery cell based on the first SOC, the second SOC, and the current information of the battery cell includes: determining the SOC change based on the first SOC and the second SOC; and calculating the capacity change information using the ampere-hour integration method based on the current information.
[0015] In this embodiment, the change in SOC is determined based on the first SOC and the second SOC, and the current information is estimated using the ampere-hour integration method to accurately determine the capacity change information. This allows for the determination of the cell's capacity parameters based on the capacity change information, thereby improving the accuracy of capacity parameter determination.
[0016] In some embodiments, the first SOC threshold includes 90%; the second SOC threshold includes 10%.
[0017] In some embodiments, according to a second aspect of the present disclosure, a cell testing apparatus for an energy storage system is provided, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the cell testing method for the energy storage system as described above based on instructions stored in the memory.
[0018] In some embodiments, according to a third aspect of this disclosure, an energy storage system is provided, comprising: a battery cell and a battery cell detection device for the energy storage system as described above.
[0019] In some embodiments, according to a fourth aspect of this disclosure, a computer-readable storage medium is provided that stores computer instructions which are executed by a processor as described above for a cell detection method for an energy storage system.
[0020] In some embodiments, according to a fifth aspect of this disclosure, a computer program product is provided, wherein the computer program product includes a computer program, which, when executed by a processor, is used to implement the cell detection method for an energy storage system as described above.
[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.
[0023] Figure 1 This is a schematic flowchart of some embodiments of the battery cell testing method disclosed herein;
[0024] Figure 2 This is a flowchart illustrating the process of determining the capacity parameter information of a battery cell in some embodiments of the battery cell testing method disclosed herein.
[0025] Figure 3 This is a schematic flowchart illustrating the process of determining the health status information of a battery cell in some embodiments of the battery cell testing method disclosed herein;
[0026] Figure 4The diagram shows some embodiments of the battery cell testing device disclosed herein.
[0027] Figure 5 The following are schematic diagrams of modules for some other embodiments of the battery cell testing device disclosed herein;
[0028] Figure 6 This is a schematic diagram of modules for some further embodiments of the battery cell testing device disclosed herein. Detailed Implementation
[0030] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.
[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least some of the embodiments of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0035] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).
[0036] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.
[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.
[0038] Figure 1 This is a flowchart illustrating some embodiments of the battery cell testing method disclosed herein. Figure 1 As shown, the cell testing method includes steps S101 to S104.
[0039] Step S101: Determine the first SOC (State of Charge) of the battery cell based on the first voltage information of the battery cell.
[0040] The battery cell can be of various types, such as lithium-ion cells, and is used to store electrical energy. The first voltage information of the battery cell is the voltage information collected by the cell in the first detection state, and this first voltage information can be obtained using various methods. For example, an energy storage system includes multiple battery cells. The energy storage system can use existing data acquisition devices to collect various data such as voltage, current, discharge time, and charging time of each cell; it can also acquire the first voltage information of the cell collected by the data acquisition device in the first detection state; after acquiring the first voltage information of the cell, the first state of charge (SOC) is determined based on this first voltage information.
[0041] Step S102: Determine the second SOC of the battery cell based on the second voltage information of the battery cell.
[0042] The second voltage information of the battery cell refers to the voltage information of the battery cell collected in the second detection state. This second voltage information can be obtained using various methods. For example, the second voltage information of the battery cell collected by a data acquisition device in the second detection state can be acquired. After acquiring the second voltage information, the second SOC is determined based on this information.
[0043] Step S103: Determine the capacity parameter information of the battery cell based on the first SOC, the second SOC, and the current information of the battery cell.
[0044] The current information of the battery cell includes the current information during the charging or discharging of the cell within the time interval between the first and second detection states. This current information includes the current magnitude and the corresponding time, and can be obtained using various methods. For example, the charging or discharging current information of the battery cell can be acquired by a data acquisition device during the time interval between the first and second detection states.
[0045] Step S104: Determine the health status information of the battery cell based on the initial capacity information and capacity parameter information of the battery cell.
[0046] The initial capacity information of a battery cell can be the capacity information of the cell under conditions such as first use. This initial capacity information can be pre-stored in the storage units of the energy storage system. State of Health (SOH) is a parameter reflecting the performance and lifespan of a battery cell. SOH information can reflect capacity changes after cell aging. Cell aging during use leads to a decrease in cell capacity. If the SOH is not corrected after the capacity decreases, there may be safety risks such as overcurrent. Based on the cell's state of health information, existing methods can be used to correct the cell's state of health parameters.
[0047] The disclosed cell testing method is easy to implement, solves the problem of difficulty in detecting cell health status and other information, improves the accuracy and reliability of health status determination, and can be used to correct cell health status parameters, thereby improving the stability and safety of energy storage system operation.
[0048] In some embodiments, the first detection state and the second detection state can be multiple states. For example, the first detection state includes: the battery cell is in a first static state and the static duration is greater than a first duration threshold, wherein, in the first detection state, the SOC of the battery cell is greater than a first SOC threshold or less than a second SOC threshold.
[0049] The second detection state includes a state where the battery cell is in a second static state and the static duration is greater than a second duration threshold. In this second detection state, the battery cell's State of Charge (SOC) is less than the second SOC threshold or greater than the first SOC threshold, where the first SOC threshold is greater than the second SOC threshold. By setting the first and second detection states when detecting the battery cell, the accuracy of determining information such as the battery cell's health status can be ensured.
[0050] The first and second duration thresholds can be the same or different. The first and second duration thresholds can be set according to detection requirements; for example, both the first and second duration thresholds can be 2 hours. The first and second SOC thresholds can also be set according to detection requirements; for example, the first SOC threshold can be 90%, and the second SOC threshold can be 10%.
[0051] During the time interval between the first detection state and the second detection state, the battery cell can be controlled to undergo discharge processing. Before the discharge processing, the SOC of the battery cell is greater than the first SOC threshold, and after the discharge processing is completed, the SOC of the battery cell is less than the second SOC threshold.
[0052] During the time interval between the first detection state and the second detection state, the battery cell can be controlled to perform charging processing. Before the charging process, the SOC of the battery cell is less than the second SOC threshold, and after the charging process is completed, the SOC of the battery cell is greater than the first SOC threshold.
[0053] When testing a battery cell, by controlling the cell to charge or discharge during the interval between the first and second testing states, the accuracy of determining information such as the cell's health status can be ensured.
[0054] In some embodiments, when testing the battery cell, if the battery cell is in a first static state and the static duration is greater than a first duration threshold of 2 hours, and the SOC of the battery cell is greater than 90% of the first SOC threshold or less than 10% of the second SOC threshold (state 1), then the battery cell is determined to be in a first testing state; the last moment when the battery cell is in this state is recorded as T1.
[0055] After the energy storage system is powered on, the cells are charged and discharged under the set operating conditions until the cutoff condition (state 2) is reached. The last moment of the cell in this state is recorded as T2. The cutoff condition can be various, for example, the cutoff condition includes the cell's SOC being less than 10% of the second SOC threshold or greater than 90% of the first SOC threshold.
[0056] If the battery cell is in the second static state and the static duration is greater than the second duration threshold of 2 hours, and the SOC of the battery cell is less than the second SOC threshold of 10% or greater than the first SOC threshold of 90% (state 3), then the battery cell is determined to be in the second detection state; the last moment when the battery cell is in this state is recorded as T3.
[0057] The battery cell can be charged and discharged under various operating conditions. For example, during the interval between the first and second detection states, starting from time T1, the battery cell is periodically charged at 30-minute intervals with set current and power parameters until the cutoff condition is met. Before charging, the battery cell's SOC is less than 10% of the second SOC threshold; after charging is complete, the battery cell's SOC is greater than 90% of the first SOC threshold.
[0058] Alternatively, during the interval between the first and second detection states, starting from time T1, the battery cell can be periodically discharged at 30-minute intervals, controlled by set operating parameters, until the cutoff condition is met. Before discharge, the battery cell's SOC is greater than 90%, and after discharge, the battery cell's SOC is less than 10%.
[0059] In some embodiments, the first SOC of the battery cell can be determined using various methods based on the first voltage information of the battery cell acquired in the first detection state. For example, the first SOC can be calculated based on the SOC-OCV (Open Circuit Voltage) curve of the battery cell and the first voltage information.
[0060] The SOC-OCV curve can be pre-stored. The SOC-OCV curve is a curve characterizing the relationship between the SOC and OCV of the battery cell. The first voltage information includes the OCV information of the battery cell. Based on the first voltage information, the first SOC corresponding to the first voltage information is calculated using the SOC-OCV curve and interpolation algorithms. Determining the first SOC through the SOC-OCV curve of the battery cell improves the efficiency and accuracy of the first SOC determination.
[0061] Based on the second voltage information of the battery cell acquired under the second detection state, the second SOC of the battery cell can be determined using various methods. For example, the second SOC can be calculated based on the SOC-OCV curve of the battery cell and the second voltage information. The second voltage information includes the OCV information of the battery cell. Based on the second voltage information, the second SOC corresponding to the second voltage information is calculated using the SOC-OCV curve and interpolation algorithms. Determining the second SOC through the SOC-OCV curve of the battery cell improves both the efficiency and accuracy of the second SOC determination.
[0062] Figure 2 This is a flowchart illustrating the process of determining the capacity parameter information of a battery cell in some embodiments of the battery cell testing method disclosed herein. Figure 2 As shown, the method for determining the capacity parameter information of the battery cell includes steps S201 to S203.
[0063] Step S201: Determine the change in SOC based on the first SOC and the second SOC.
[0064] Several methods can be used to determine the change in SOC. For example, the difference between the first SOC and the second SOC can be calculated, and the absolute value of this difference can be used as the change in SOC.
[0065] Step S202: Based on the current information, determine the capacity change information of the battery cell.
[0066] The current information refers to the charging or discharging current of the battery cell during the time interval between the first and second detection states. Based on this current information, various methods can be used to determine the cell's capacity change information. One method is the ampere-hour integration method, which calculates the capacity change based on the current information. This ampere-hour integration method is then used to estimate the capacity of the current information, thereby determining the cell's capacity parameters based on the capacity change information.
[0067] For example, current information includes current magnitude and time information. Existing ampere-hour integration methods can be used to calculate capacity change information based on current and time. The formula for calculating the capacity change information of a battery cell is:
[0068] ΔCap = (1-1);
[0069] Wherein, ΔCap represents the capacity change information of the battery cell; I represents the current magnitude of the battery cell during the charging or discharging process in the time interval between the first detection state and the second detection state; and [T1, T2] represents the time interval during the charging or discharging process in the battery cell in the time interval between the first detection state and the second detection state.
[0070] Step S203: Determine capacity parameter information based on capacity change information and SOC change amount.
[0071] The change in SOC is determined by the first SOC and the second SOC, and the capacity change information of the cell is determined by the current information. The capacity parameter information is determined based on the capacity change information and the change in SOC, which improves the accuracy of the capacity parameter information determination, and thus improves the accuracy of the health status information determination.
[0072] Various methods can be used to determine capacity parameter information based on capacity change information and SOC change. For example, a first ratio of capacity change information to SOC change can be calculated and used as the capacity parameter information. By using the first ratio of capacity change information to SOC change as the capacity parameter information, the accuracy of capacity parameter determination is improved.
[0073] Various methods can be used to determine the health status of a battery cell based on its initial capacity information and capacity parameter information. For example, a second ratio of the capacity parameter information to the initial capacity information can be calculated and used as the health status information. By using this second ratio, the accuracy of health status determination is improved.
[0074] Figure 3 This is a schematic flowchart illustrating the process of determining the health status information of a battery cell in some embodiments of the battery cell testing method disclosed herein. Figure 3 As shown, the method for determining the health status information of the battery cell includes steps S301 to S305.
[0075] Step S301: Calculate the first SOC based on the SOC-OCV curve of the battery cell and the first voltage information.
[0076] The SOC-OCV curves of each battery cell are pre-stored in the storage unit of the energy storage system. When each battery cell is in its first detection state, the first voltage information of each cell is collected. Based on the SOC-OCV curves and the first voltage information of each cell, the first SOC of each cell is calculated as SOC1 using an interpolation method.
[0077] Step S302: Calculate the second SOC based on the SOC-OCV curve of the battery cell and the second voltage information.
[0078] During the time interval between the first and second detection states, the battery cells are controlled to charge or discharge. In the second detection state, the second voltage information of each battery cell in the energy storage system is collected. Based on the SOC-OCV curve and the second voltage information of each battery cell, the second SOC of each battery cell is calculated as SOC2 using an interpolation method.
[0079] Step S303: Based on the current information, determine the capacity change information of the battery cell.
[0080] The current information refers to the charging or discharging current of each cell during the time interval between the first and second detection states. Based on the current information, the ampere-hour integration method is used to calculate the capacity change information ΔCap of each cell by integrating the current information (including current magnitude and time).
[0081] Step S304: Calculate the first ratio of capacity change information to SOC change amount, and use the first ratio as capacity parameter information.
[0082] The change in SOC can be represented as ΔSOC = abs(SOC1 – SOC2), where abs() is the absolute value function. The first ratio of the capacity change information to the change in SOC is calculated as the capacity parameter information. The capacity parameter information of each cell is Cap = ΔCap / ΔSOC, which yields the capacity distribution data of the cells under the current aging dimension.
[0083] Step S305: Calculate the second ratio of the capacity parameter information to the initial capacity information, and use the second ratio as the health status information.
[0084] The second ratio of the capacity distribution information to the initial capacity information can be calculated as the health status information. The health status information of each cell is SOH = Cap / Cap0.
[0085] In some embodiments, the energy storage system includes an energy storage cabinet, in which multiple battery cells are arranged in series. The initial capacity information Cap0 of each battery cell can be determined during the cell production stage and stored in the storage unit; the SOC-OCV curves of each battery cell can be the same or different, and the SOC-OCV curves of the battery cells are predetermined and stored.
[0086] After the energy storage cabinet is integrated and assembled, and when each cell of the energy storage system is in the first detection state, the first voltage information of each cell is collected. Based on the SOC-OCV curve and the first voltage information of each cell, the first SOC is calculated as SOC1 using an interpolation method.
[0087] During the time interval between the first and second detection states, the battery cells are controlled to charge or discharge according to preset operating condition data. Based on the current information of each battery cell during the charging or discharging process during the time interval between the first and second detection states, the ampere-hour integration method is used to calculate the capacity change information ΔCap of each battery cell by integrating the current data (including current magnitude and time). Since all battery cells are connected in series, the capacity change ΔCap calculated based on the ampere-hour integration method can be equal for each battery cell.
[0088] The second voltage information of each cell is acquired under the second detection state. Based on the SOC-OCV curve of the cell and the second voltage information, the second SOC of each cell is calculated as SOC2.
[0089] Calculate the SOC change of each cell ΔSOC = ABS(SOC1 – SOC2), calculate the capacity parameter information of each cell (the actual capacity distribution data of each cell) Cap = ΔCap / ΔSOC; calculate the current health status information of each cell SOH = Cap / Cap0; based on the health status information of each cell, existing methods can be used to correct the health status parameters of the cells that need correction.
[0090] The cell detection method in the above embodiments determines the cell's capacity parameters based on the cell's first SOC in the first detection state, second SOC in the second detection state, and current information. Based on the initial capacity information and capacity parameters, it determines the cell's health status. This method can detect cells in various application scenarios, is easy to implement, and solves the problem of difficulty in detecting cell health status and other information. It accurately determines the cell's health status and other information, improving the accuracy and reliability of this determination. Based on the health status information, the cell's health status parameters can be corrected in a timely manner, improving the stability and safety of the energy storage system.
[0091] In some embodiments, such as Figure 4 As shown, this disclosure provides a battery cell testing device, including a first SOC determination module 401, a second SOC determination module 402, a capacity determination module 403, and a health determination module 404.
[0092] The first SOC determination module 401 determines the first state of charge (SOC) of the battery cell based on the first voltage information of the battery cell, wherein the first voltage information is the voltage information of the battery cell collected in the first detection state. For example, the first SOC determination module 401 calculates the first SOC based on the SOC-OCV curve of the battery cell and the first voltage information.
[0093] The second SOC determination module 402 determines the second SOC of the battery cell based on the second voltage information of the battery cell, wherein the second voltage information is the voltage information of the battery cell collected in the second detection state. For example, the second SOC determination module 402 calculates the second SOC based on the SOC-OCV curve of the battery cell and the second voltage information.
[0094] The capacity determination module 403 determines the capacity parameter information of the battery cell based on the first SOC, the second SOC, and the current information of the battery cell. The health determination module 404 determines the health status information of the battery cell based on the initial capacity information and the capacity parameter information. For example, the health determination module 404 calculates a second ratio between the capacity parameter information and the initial capacity information, and uses the second ratio as the health status information.
[0095] In some embodiments, the capacity determination module 403 determines the SOC change based on the first SOC and the second SOC; the capacity determination module 403 determines the capacity change information of the battery cell based on the current information; and the capacity determination module 403 determines the capacity parameter information based on the capacity change information and the SOC change.
[0096] For example, the capacity determination module 403 calculates the capacity change information based on the current information using the ampere-hour integration method; the capacity determination module 403 calculates the first ratio of the capacity change information to the SOC change, and uses the first ratio as the capacity parameter information.
[0097] In some embodiments, such as Figure 5 As shown, this disclosure provides a battery cell testing device, including a first SOC determination module 401, a second SOC determination module 402, a capacity determination module 403, a health determination module 404, and a charge / discharge control module 405.
[0098] The charge / discharge control module 405 controls the battery cell to perform discharge processing during the time interval between the first detection state and the second detection state; wherein, before the discharge processing, the SOC of the battery cell is greater than the first SOC threshold, and after the discharge processing is completed, the SOC of the battery cell is less than the second SOC threshold.
[0099] The charge / discharge control module 405 controls the battery cell to perform charging during the time interval between the first detection state and the second detection state; wherein, before the charging process, the SOC of the battery cell is less than the second SOC threshold, and after the charging process is completed, the SOC of the battery cell is greater than the first SOC threshold.
[0100] The cell testing device described in the above embodiments can test cells in various application scenarios. The testing method is easy to implement and solves the problem of difficulty in detecting cell health status information. It can accurately determine cell health status information, improve the accuracy and reliability of health status information, and can be used to correct cell health status parameters, thereby improving the stability and safety of energy storage system operation.
[0101] Figure 6 This is a schematic diagram of some embodiments of the battery cell testing apparatus according to the present disclosure. Figure 6 As shown, the battery cell testing device may include a memory 501, a processor 502, a communication interface 503, and a bus 504. The memory 501 is used to store instructions, and the processor 502 is coupled to the memory 501. The processor 502 is configured to execute the battery cell testing method described above based on the instructions stored in the memory 501.
[0102] The memory 501 can be a high-speed RAM, non-volatile memory, or a memory array. The memory 501 may also be divided into blocks, and these blocks can be combined into virtual volumes according to certain rules. The processor 502 can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the cell detection method of this disclosure.
[0103] In some embodiments, this disclosure provides an energy storage system including a battery cell and a battery cell detection device as described in any of the above embodiments.
[0104] In some embodiments, this disclosure provides a computer-readable storage medium storing computer instructions that are executed by a processor as in any of the above embodiments for failure detection.
[0105] Computer-readable storage media may take the form of any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples (not an exhaustive list) of readable storage media may include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0106] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0107] Embodiments of this disclosure may also be computer program products, including computer program instructions that, when executed by a processor, cause the processor to perform the steps in the failure detection methods according to various embodiments of this disclosure as described in the "Exemplary Methods" section above.
[0108] The steps of the methods disclosed herein are not limited to the specific order described above, unless otherwise specifically stated. Furthermore, in some embodiments, this disclosure may also be implemented as a program recorded on a recording medium, the program including machine-readable instructions for implementing the methods according to this disclosure. Therefore, this disclosure also covers recording media storing programs for performing the methods according to this disclosure.
[0109] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method of detecting a cell of an energy storage system, wherein, The energy storage system comprises an energy storage cabinet, and a plurality of battery cells are arranged in the energy storage cabinet, and the battery cell detection method comprises the following steps: In the case that the battery cell is in a first detection state, first voltage information of the battery cell is collected; The first detection state comprises a state in which the battery cell is in a first stationary state and a stationary duration is greater than a first duration threshold, and in the first detection state, the SOC of the battery cell is greater than a first SOC threshold or less than a second SOC threshold, and the first SOC threshold is greater than the second SOC threshold; Based on the first voltage information of the battery cell, a first SOC of the battery cell is determined; In the case that the battery cell is in a second detection state, second voltage information of the battery cell is collected; The second detection state comprises a state in which the battery cell is in a second stationary state and a stationary duration is greater than a second duration threshold, and in the second detection state, the SOC of the battery cell is less than the second SOC threshold or greater than the first SOC threshold; and in an interval period between the first detection state and the second detection state, the battery cell is controlled to be subjected to periodic charging or discharging treatment; Based on the second voltage information of the battery cell, a second SOC of the battery cell is determined; According to the first SOC, the second SOC and current information of the battery cell in the interval period, capacity parameter information of the battery cell is determined; According to initial capacity information of the battery cell and the capacity parameter information, health state information of the battery cell is determined.
2. The method of claim 1, wherein, The first voltage information is OCV information of the battery cell in the first detection state, and the determination of the first SOC of the battery cell based on the first voltage information of the battery cell comprises the following steps: According to a SOC-OCV curve of the battery cell and based on the first voltage information, the first SOC is calculated.
3. The method of claim 1, wherein, The second voltage information is OCV information of the battery cell in the second detection state, and the determination of the second SOC of the battery cell based on the second voltage information of the battery cell comprises the following steps: According to a SOC-OCV curve of the battery cell and based on the second voltage information, the second SOC is calculated.
4. The method of claim 1, further comprising: In the interval period, the battery cell is controlled to be subjected to periodic discharging treatment; wherein, before the discharging treatment is performed, the SOC of the battery cell is greater than the first SOC threshold, and after the discharging treatment is completed, the SOC of the battery cell is less than the second SOC threshold.
5. The method of claim 1, further comprising: In the interval period, the battery cell is controlled to be subjected to periodic charging treatment; wherein, before the charging treatment is performed, the SOC of the battery cell is less than the second SOC threshold, and after the charging treatment is completed, the SOC of the battery cell is greater than the first SOC threshold.
6. The method of claim 1, wherein, The determination of the capacity parameter information of the battery cell according to the first SOC, the second SOC and the current information of the battery cell comprises the following steps: Based on the first SOC and the second SOC, a SOC variation amount is determined; Based on the current information, the capacity change information is calculated using an ampere-hour integration method.
7. The method of any one of claims 1 to 6, wherein, the first SOC threshold comprises 90%; the second SOC threshold comprises 10%.
8. An electric cell detection device of an energy storage system, comprising: a memory; and a processor coupled to the memory, the processor configured to perform the electric cell detection method of the energy storage system according to any one of claims 1 to 7 based on instructions stored in the memory.
9. An energy storage system, comprising: an electric cell, and the electric cell detection device of the energy storage system according to claim 8.
10. A computer readable storage medium storing computer instructions, the instructions being executed by a processor to perform the electric cell detection method of the energy storage system according to any one of claims 1 to 7.
11. A computer program product, wherein, The computer program product comprises a computer program, the computer program being executed by a processor to implement the electric cell detection method of the energy storage system according to any one of claims 1 to 7.