Method, device and equipment for estimating battery system health state value and storage medium

Abstract

The application discloses a battery system health state value estimation method, device and equipment and a storage medium. The battery system comprises a plurality of single cells. The estimation method comprises the following steps: correcting a state of charge value of each single cell according to a current voltage of the single cell, so as to obtain a current state of charge difference value of the battery system; determining a discharge capacity of the battery system according to an initial state of charge difference value and the current state of charge difference value of the battery system; and determining the battery system health state value according to the discharge capacity and the minimum value in single cell health state values. By simultaneously introducing the discharge capacity of the battery system and the minimum value in the single cell health state values when calculating the battery system health state value, the calculated battery system health state value can reflect the capacity attenuation of the entire battery system, and the estimation accuracy of the battery system health state value is improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a method, apparatus, device and storage medium for estimating the state of health value of a battery system. Background Technology

[0002] Battery State of Health (SOH) reflects the health status of a battery, including performance characteristics such as capacity, power, and internal resistance. Currently, when calculating the state of health value of an electric vehicle's battery system, the main approach is to calculate the state of health value of each individual cell based on the changes in its state of charge (SOC) and capacity. The minimum value among these state of health values ​​is then determined as the overall battery system state of health value.

[0003] When battery cells are connected in series and parallel to form a battery system, the battery system may experience cell imbalance due to factors such as differences in cell manufacturing or self-discharge. In this case, the health status value of the battery system calculated using the above method will be too high. Summary of the Invention

[0004] Embodiments of this application provide a method, apparatus, device, and storage medium for estimating the state of health of a battery system, thereby improving the accuracy of the estimation of the state of health of the battery system.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part by practice of this application.

[0006] According to a first aspect of the present application, a method for estimating the state of health (SQ) value of a battery system is provided, the battery system comprising multiple individual battery cells, the estimation method comprising:

[0007] The state of charge (SOC) value of each individual cell is corrected based on the current voltage of each individual cell to obtain the current SOC difference of the battery system.

[0008] The discharge capacity of the battery system is determined based on the initial state-of-charge difference and the current state-of-charge difference of the battery system.

[0009] The battery system health status value is determined based on the minimum value between the discharge capacity and the individual cell health status value.

[0010] In some embodiments of this application, based on the foregoing scheme, determining the battery system health status value according to the minimum value between the discharge capacity and the individual cell health status value includes:

[0011] The weight of the discharge capacity is determined based on the difference in the current state of charge.

[0012] The battery system health status value is determined based on the minimum value among the discharge capacity, the weight, and the individual cell health status value.

[0013] In some embodiments of this application, based on the foregoing scheme, determining the weight of the discharge capacity according to the current state of charge difference includes:

[0014] Obtain the previous state of charge difference of the battery system;

[0015] The weight of the discharge capacity is obtained by quoting the difference between the current state of charge and the previous state of charge with the current state of charge.

[0016] In some embodiments of this application, based on the foregoing scheme, the step of correcting the state of charge (SOC) value of each individual cell according to its current voltage to obtain the current SOC difference of the battery system includes:

[0017] The current state of charge value of each individual cell is obtained by looking up a table based on the current voltage of each individual cell.

[0018] The difference between the maximum value and the minimum value in the current state of charge is determined as the current state of charge difference.

[0019] In some embodiments of this application, based on the foregoing scheme, after correcting the state of charge value of each individual cell according to its current voltage to obtain the current state of charge difference of the battery system, the estimation method further includes:

[0020] Determine whether the current state of charge difference is greater than the initial state of charge difference;

[0021] If the current state of charge difference is greater than the initial state of charge difference, the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference of the battery system is performed.

[0022] If the current state of charge difference is less than the initial state of charge difference, the minimum value among the individual cell health state values ​​is determined as the battery system health state value.

[0023] In some embodiments of this application, based on the foregoing scheme, the estimation method further includes:

[0024] Obtain the rated capacity of each individual cell, as well as the amount of capacity change and the amount of state of charge change between two state of charge value corrections;

[0025] The individual cell health status value is obtained based on the rated capacity, the capacity change, and the state of charge change.

[0026] In some embodiments of this application, based on the foregoing scheme, the estimation method further includes:

[0027] Obtain the maximum voltage difference between the individual battery cells;

[0028] The initial state of charge difference is obtained by looking up the table based on the maximum voltage difference.

[0029] According to a second aspect of the present application, a device for estimating the state of health value of a battery system is provided, the battery system comprising a plurality of individual battery cells, the estimation device comprising:

[0030] A state of charge correction unit is used to correct the state of charge value of each individual cell according to the current voltage of each individual cell, so as to obtain the current state of charge difference of the battery system.

[0031] The discharge capacity determination unit is used to determine the discharge capacity of the battery system based on the initial state-of-charge difference and the current state-of-charge difference of the battery system.

[0032] A battery health status value determination unit is used to determine the battery system health status value based on the minimum value between the discharge capacity and the individual cell health status value.

[0033] In some embodiments of this application, based on the foregoing scheme, the battery health state value determination unit is further configured to determine the weight of the discharge capacity according to the current state of charge difference;

[0034] The battery system health status value is determined based on the minimum value among the discharge capacity, the weight, and the individual cell health status value.

[0035] In some embodiments of this application, based on the foregoing scheme, the battery health status value determination unit is further configured to obtain the previous state of charge difference of the battery system;

[0036] The weight of the discharge capacity is obtained by quoting the difference between the current state of charge and the previous state of charge with the current state of charge.

[0037] In some embodiments of this application, based on the foregoing scheme, the state of charge correction unit is further configured to look up a table according to the current voltage of each individual cell to obtain the current state of charge value of each individual cell;

[0038] The difference between the maximum value and the minimum value in the current state of charge is determined as the current state of charge difference.

[0039] In some embodiments of this application, based on the foregoing scheme, the estimation device further includes a judgment unit for judging whether the current state of charge difference is greater than the initial state of charge difference;

[0040] The discharge capacity determination unit is further configured to perform the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference when the current state of charge difference is greater than the initial state of charge difference;

[0041] The battery health status value determination unit is further configured to determine the minimum value among the individual cell health status values ​​as the battery system health status value when the current state of charge difference is less than the initial state of charge difference.

[0042] In some embodiments of this application, based on the foregoing scheme, the estimation device further includes a single cell health status value determination unit, used to obtain the rated capacity of each single cell, as well as the capacity change and state of charge change between two state of charge value corrections;

[0043] The individual cell health status value is obtained based on the rated capacity, the capacity change, and the state of charge change.

[0044] In some embodiments of this application, based on the foregoing scheme, the estimation device further includes an initial state of charge difference determination unit, used to obtain the maximum voltage difference between the individual cells;

[0045] The initial state of charge difference is obtained by looking up the table based on the maximum voltage difference.

[0046] According to a third aspect of the present application, a device for estimating the state of health of a battery system is provided. The device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0047] According to a fourth aspect of the embodiments of this application, a computer-readable storage medium is provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0048] In this application, the current state of charge (SOC) value of each individual cell is corrected based on its current voltage to obtain the current SOC difference of the battery system. The discharge capacity of the battery system is determined based on the initial SOC difference and the current SOC difference. The battery system's health state value is determined based on the minimum of the discharge capacity and the individual cell's health state value. By simultaneously incorporating the minimum of the battery system's discharge capacity and the individual cell's health state value when calculating the battery system's health state value, the calculated battery system health state value reflects the capacity decay of the entire battery system, thus improving the estimation accuracy of the battery system's health state value.

[0049] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0050] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0051] Figure 1 This is a flowchart illustrating a method for estimating the state of health of a battery system in one embodiment;

[0052] Figure 2 This is a flowchart illustrating step 103 in one embodiment;

[0053] Figure 3 This is a flowchart illustrating a method for estimating the state of health of a battery system in another embodiment;

[0054] Figure 4 This is a structural block diagram of a battery system health state estimation device in one embodiment;

[0055] Figure 5 This is an internal structural diagram of a device for estimating the state of health of a battery system in one embodiment. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0057] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0058] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0059] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0061] The battery system health state estimation method provided in this application can be applied to battery systems comprising multiple individual cells. Current methods for estimating battery system health state typically determine the health state value of each individual cell and then use the minimum of these individual cell health state values ​​as the overall battery system health state value. However, due to differences among individual cells within a battery system—such as manufacturing variations or inconsistencies in self-discharge—voltage differences can exist between cells, causing some cells to experience excessively rapid capacity decay. This results in the actual charge / discharge capacity decay of the entire battery system exceeding that of a single cell. If the health state value of a single cell is used as the overall battery system health state value using the aforementioned method, the calculated battery system health state value will be too high. This embodiment considers the inconsistencies among cells and incorporates the battery system's discharge capacity when calculating the battery system health state value. This allows the calculated battery system health state value to reflect the overall capacity decay of the battery system, improving the estimation accuracy of the battery system health state value.

[0062] Figure 1 This is a flowchart illustrating a method for estimating the state of health of a battery system in one embodiment, as shown below. Figure 1 As shown, a method for estimating the state of health of a battery system is provided, which may include the following steps:

[0063] Step 101: Correct the state of charge value of each individual cell based on the current voltage of each individual cell to obtain the current state of charge difference of the battery system.

[0064] It should be understood that during the charging and discharging process of a battery system, the voltage of a single cell is constantly changing, and the current voltage refers to the voltage of the single cell at the current moment.

[0065] After correcting the state of charge (SOC) value of each individual cell based on its current voltage, the current SOC value of each individual cell can be obtained. Based on the current SOC value of each individual cell, the current SOC difference of the entire battery system can be determined.

[0066] Among them, the current state of charge difference refers to the difference in the current state of charge values ​​of different individual cells.

[0067] In one example, the current state of charge (SOC) value of each individual cell can be obtained by looking up a table based on the current voltage of each individual cell; the difference between the maximum value and the minimum value of the current SOC value is determined as the current SOC difference.

[0068] Typically, each individual cell corresponds to an open circuit voltage (OCV)-SOC table. The OCV-SOC table can be consulted based on the current voltage of the individual cell to obtain a corrected state of charge (SOC) value, which is then used as the current SOC value for that individual cell. Considering cell consistency, this embodiment uses the difference between the maximum and minimum values ​​of the current SOC value as the current SOC difference.

[0069] Assuming that after the first state-of-charge (SOC) correction, the maximum current SOC value in the battery system is... 1max The minimum value of the current state of charge is SOC. 1min Then the current state of charge difference ΔSOC1 = SOC 1max -SOC 1min .

[0070] After the second state-of-charge (SOC) correction, the maximum current SOC value in the battery system is [value missing]. 2max The minimum value of the current state of charge is SOC. 2min Then the current state of charge difference ΔSOC2 = SOC 2max-SOC 2min And so on.

[0071] In one example, after obtaining the current state of charge difference of the battery system, the initial state of charge difference of the battery system can also be obtained, and it can be determined whether the current state of charge difference is greater than the initial state of charge difference. If the current state of charge difference is greater than the initial state of charge difference, the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference is executed. If the current state of charge difference is less than the initial state of charge difference, the minimum value among the individual cell health state values ​​is determined as the battery system health state value.

[0072] Since it is impossible to guarantee that all cells are completely identical during the assembly of the battery system, there will be a certain voltage difference after the battery system is assembled and removed from the production line. However, this voltage difference will be controlled within a certain range. Therefore, the maximum voltage difference between individual cells can be obtained. The initial state of charge difference can be obtained by looking up the table based on the maximum voltage difference.

[0073] It should be noted that when the current state of charge difference ΔSOC1 after the first correction is less than the initial state of charge difference of the battery system, the influence of the state of charge difference is not considered, and the minimum value among the individual cell health status values ​​can be directly determined as the battery system health status value. When the current state of charge difference ΔSOC1 after the first correction is greater than the initial state of charge difference of the battery system, the battery system health status value needs to be calculated based on the current state of charge difference. This can effectively improve the calculation efficiency of the battery system health status value.

[0074] Step 102: Determine the discharge capacity of the battery system based on the difference between the initial state of charge and the current state of charge.

[0075] Taking the initial state of charge difference as ΔSOC0 and the current state of charge difference as ΔSOC as an example, the discharge capacity of the battery system can be calculated using 1-(ΔSOC-ΔSOC0).

[0076] During implementation, the fluctuation of discharge capacity 1 - (ΔSOC - ΔSOC0) should not be too large to prevent significant jumps in the battery system's state of health. Therefore, the fluctuation of discharge capacity can be compared with a preset threshold. When the fluctuation of discharge capacity exceeds the preset threshold, the discharge capacity is determined based on the difference between the initial state of charge and the previous state of charge.

[0077] Step 103: Determine the battery system health status value based on the minimum value between the discharge capacity and the individual cell health status value.

[0078] To obtain the minimum value among the individual cell health status values, one can first obtain the individual cell health status value for each individual cell, and then select the minimum value from among them. For example, when the battery system consists of cell A, cell B, and cell C, it is necessary to obtain the individual cell health status values ​​of cell A, cell B, and cell C, and then select the minimum value from these three individual cell health status values.

[0079] Alternatively, the state of health (SHS) value for each individual cell can be calculated first, and then the minimum value can be selected. The SHS value can be calculated in several ways. In one example, it can be calculated based on parameters such as the depth of discharge, ambient temperature, and calendar lifetime of the individual cell, along with a pre-defined formula. In another example, the rated capacity of each individual cell, as well as the capacity change and SHS change between two SHS corrections, can be obtained; based on the rated capacity, capacity change, and SHS change, the SHS value can be derived.

[0080] It should be understood that during the charging and discharging process of the battery system, the state of charge (SOC) value of each individual cell is continuously corrected. After each SOC correction is completed, the health status value of the individual cell is obtained based on the change in capacity between the two SOC corrections, the change in SOC between the two SOC corrections, the rated capacity, the change in capacity, and the change in SOC.

[0081] Assuming the capacity change between two state-of-charge (POC) corrections is deltaQ, the POC change between two POC corrections is deltaSOC, and the rated capacity is Qr, then the cell health value can be calculated using the formula... Calculated.

[0082] When determining the state of health (SQH) value of a battery system, different weights can be assigned to the minimum SQH value and discharge capacity of individual cells. The SQH value of the battery system is then calculated using these weights and a pre-defined formula. In one example, the SQH value of the battery system can be calculated using the following formula:

[0083]

[0084] Where γ is the weight, which can be set according to specific circumstances; this embodiment does not impose any restrictions on it. SOH1 is the battery system health status value. ΔQ represents the minimum value among the single-cell health status values, deltaQ represents the capacity change between two state-of-charge (SOC) corrections, deltaSOC represents the SOC change between two SOC corrections, Qr represents the rated capacity, ΔSOC represents the current SOC difference, and ΔSOC0 represents the initial SOC difference.

[0085] This embodiment corrects the state of charge (SOC) value of each individual cell based on its current voltage to obtain the current SOC difference of the battery system. The discharge capacity of the battery system is determined based on the initial SOC difference and the current SOC difference. Finally, the battery system's state of health (SOC) value is determined based on the minimum of the discharge capacity and the individual cell's SOC value. By incorporating both the battery system's discharge capacity and the minimum individual cell SOC value into the calculation of the battery system's SOC value, the calculated SOC value reflects the overall capacity decay of the battery system, thus improving the accuracy of the SOC estimation.

[0086] In one embodiment, such as Figure 2 As shown, step 103 may include the following steps:

[0087] Step 201: Determine the weight of the discharge capacity based on the current state of charge difference;

[0088] Step 202: Determine the battery system health status value based on the minimum value among discharge capacity, weight, and individual cell health status value.

[0089] The rate of change of the current state of charge difference can be used as the weight of the discharge capacity. Specifically, the previous state of charge difference of the battery system can be obtained; the difference between the current state of charge difference and the previous state of charge difference can be divided by the current state of charge difference to obtain the weight of the discharge capacity.

[0090] Taking the current state of charge difference as the state of charge difference corresponding to the second correction as an example, the weight of the discharge capacity can be calculated using the formula: The calculation is performed, where ΔSOC2 is the current state of charge difference and ΔSOC1 is the previous state of charge difference. Correspondingly, the battery system health state value can be calculated using the following formula:

[0091]

[0092] It should be understood that, because there is a corresponding relationship between the voltage difference of the battery cell and the state of charge difference, the larger the voltage difference, the larger the state of charge difference. Therefore, the state of charge difference can well reflect the impact of the battery cell voltage difference on the capacity decay of the battery system.

[0093] In this embodiment, the weight of the discharge capacity is determined based on the current state of charge difference. The battery system health status value is determined based on the minimum value among the discharge capacity, weight, and individual cell health status value. When the voltage difference of the individual cells deteriorates rapidly, the capacity decay caused by the voltage difference increases. At this time, the calculated battery system health status value is smaller, further reducing the battery system health status value and improving the calculation accuracy of the battery system health status value.

[0094] Figure 3 This is a flowchart illustrating a method for estimating the state of health of a battery system in another embodiment, as shown below. Figure 3 As shown, a method for estimating the state of health of a battery system is provided, which may include the following steps:

[0095] Step 301: Obtain the maximum voltage difference between individual cells, and look up the table based on the maximum voltage difference to obtain the initial state of charge difference of the battery system.

[0096] Step 302: Based on the current voltage of each individual cell, look up the table to obtain the current state of charge value of each individual cell, and determine the difference between the maximum value and the minimum value of the current state of charge value as the current state of charge difference of the battery system.

[0097] Step 303: Determine whether the current state of charge difference is greater than the initial state of charge difference;

[0098] Step 304: If the current state of charge difference is greater than the initial state of charge difference, determine the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference.

[0099] Step 305: Determine the weight of the discharge capacity based on the rate of change of the current state of charge difference;

[0100] Step 306: Determine the battery system health status value based on the minimum value among discharge capacity, weight, and individual cell health status value.

[0101] This embodiment takes into account the impact of battery consistency factors (such as voltage differences or state of charge differences between individual cells) on the battery system's state of health value. It calculates the discharge capacity at the battery system level by using the state of charge difference, and iteratively estimates the battery system's state of health value based on the rate of change of discharge capacity and state of charge difference. This further improves the accuracy of the battery system's state of health value estimation and provides a basis for subsequent battery maintenance.

[0102] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0103] Based on the same inventive concept, this application also provides a device for estimating the state of health of a battery system, wherein the battery system includes multiple individual battery cells, such as... Figure 4 As shown, the battery system health state value estimation device includes: a state of charge correction unit 401, a discharge capacity determination unit 402, and a battery health state value determination unit 403, wherein: the state of charge correction unit 401 is used to correct the state of charge value of each individual cell based on the current voltage of each individual cell to obtain the current state of charge difference of the battery system; the discharge capacity determination unit 402 is used to determine the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference of the battery system; and the battery health state value determination unit 403 is used to determine the battery system health state value based on the minimum value between the discharge capacity and the individual cell health state value.

[0104] In some embodiments of this application, based on the aforementioned scheme, the battery health status value determination unit 403 is further configured to determine the weight of the discharge capacity based on the current state of charge difference; and to determine the battery system health status value based on the minimum value among the discharge capacity, the weight, and the individual cell health status value.

[0105] In some embodiments of this application, based on the aforementioned scheme, the battery health status value determination unit 403 is further configured to obtain the previous state of charge difference of the battery system; and to obtain the weight of the discharge capacity by quotienting the difference between the current state of charge difference and the previous state of charge difference with the current state of charge difference.

[0106] In some embodiments of this application, based on the aforementioned scheme, the state of charge correction unit 401 is further configured to look up a table according to the current voltage of each individual cell to obtain the current state of charge value of each individual cell; and to determine the difference between the maximum value and the minimum value in the current state of charge value as the current state of charge difference.

[0107] In some embodiments of this application, based on the aforementioned scheme, the estimation device further includes a judgment unit (not shown) for judging whether the current state of charge difference is greater than the initial state of charge difference; the discharge capacity determination unit 402 is further used to perform the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference when the current state of charge difference is greater than the initial state of charge difference; the battery health status value determination unit 403 is further used to determine the minimum value among the individual cell health status values ​​as the battery system health status value when the current state of charge difference is less than the initial state of charge difference.

[0108] In some embodiments of this application, based on the aforementioned scheme, the estimation device further includes a single cell health status value determination unit (not shown), used to obtain the rated capacity of each single cell, as well as the amount of capacity change and the amount of state of charge change between two state of charge value corrections; and to obtain the single cell health status value based on the rated capacity, the amount of capacity change and the amount of state of charge change.

[0109] In some embodiments of this application, based on the aforementioned scheme, the estimation device further includes an initial state of charge difference determination unit (not shown), used to obtain the maximum voltage difference between individual cells; and to obtain the initial state of charge difference by looking up a table based on the maximum voltage difference.

[0110] Each module in the aforementioned battery system health status estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0111] Based on the same inventive concept, embodiments of this application also provide a device for estimating the health status value of a battery system. Figure 5 Here is an internal structure diagram of a device for estimating the state of health of a battery system in one embodiment, such as... Figure 5 As shown, the battery system health status estimation device includes one or more memories 504, one or more processors 502, and at least one computer program (program code) stored in the memory 504 and executable on the processor 502. When the processor 502 executes the computer program, it implements the battery system health status estimation method as described above.

[0112] Among them, Figure 5In this document, a bus architecture (represented by bus 500) is used. Bus 500 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 502 and memory represented by memory 504. Bus 500 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 505 provides an interface between bus 500 and receiver 501 and transmitter 503. Receiver 501 and transmitter 503 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 502 is responsible for managing bus 500 and general processing, while memory 504 can be used to store data used by processor 502 during operation.

[0113] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the battery system health state estimation device to which the present application is applied. The specific battery system health state estimation device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0114] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it performs the following steps: correcting the state of charge (SOC) value of each individual cell based on the current voltage of each individual cell to obtain the current SOC difference of the battery system; determining the discharge capacity of the battery system based on the initial SOC difference and the current SOC difference; and determining the battery system health value based on the minimum value between the discharge capacity and the individual cell health value.

[0115] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining the weight of the discharge capacity based on the current state of charge difference; and determining the battery system health state value based on the minimum value among the discharge capacity, the weight, and the individual cell health state value.

[0116] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the previous state of charge difference of the battery system; and quotienting the difference between the current state of charge difference and the previous state of charge difference with the current state of charge difference to obtain the weight of the discharge capacity.

[0117] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: looking up a table based on the current voltage of each individual cell to obtain the current state of charge value of each individual cell; and determining the difference between the maximum value and the minimum value in the current state of charge values ​​as the current state of charge difference.

[0118] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: determining whether the current state of charge difference is greater than the initial state of charge difference; if the current state of charge difference is greater than the initial state of charge difference, performing the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference of the battery system; if the current state of charge difference is less than the initial state of charge difference, determining the minimum value among the individual cell health state values ​​as the battery system health state value.

[0119] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the rated capacity of each individual cell, as well as the amount of capacity change and the amount of state of charge change between two state of charge value corrections; and obtaining the individual cell health status value based on the rated capacity, the amount of capacity change, and the amount of state of charge change.

[0120] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the maximum voltage difference between individual cells; and looking up the initial state of charge difference in a table based on the maximum voltage difference.

[0121] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0122] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0123] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0124] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0125] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for estimating the state of health of a battery system, characterized in that, The battery system comprises multiple individual battery cells, and the estimation method includes: The state of charge (SOC) value of each individual cell is corrected based on the current voltage of each individual cell to obtain the current SOC difference of the battery system. The discharge capacity of the battery system is determined based on the initial state-of-charge difference and the current state-of-charge difference of the battery system. The battery system health status value is determined based on the minimum value between the discharge capacity and the individual cell health status value. Determining the battery system health status value based on the minimum value between the discharge capacity and the individual cell health status value includes: Obtain the previous state of charge difference of the battery system; The weight of the discharge capacity is obtained by quoting the difference between the current state of charge difference and the previous state of charge difference with the current state of charge difference. The battery system health status value is determined based on the minimum value among the discharge capacity, the weight, and the individual cell health status value. Wherein, the discharge capacity is based on 1-( SOC- Calculated using SOC0, SOC0 is the difference in initial state of charge. SOC is the difference between the current state of charge and the current state of charge.

2. The estimation method according to claim 1, characterized in that, The step of correcting the state of charge (SOC) value of each individual cell based on its current voltage to obtain the current SOC difference of the battery system includes: The current state of charge value of each individual cell is obtained by looking up a table based on the current voltage of each individual cell. The difference between the maximum value and the minimum value in the current state of charge is determined as the current state of charge difference.

3. The estimation method according to claim 1, characterized in that, After correcting the state of charge (SOC) value of each individual cell based on its current voltage to obtain the current SOC difference of the battery system, the estimation method further includes: Determine whether the current state of charge difference is greater than the initial state of charge difference; If the current state of charge difference is greater than the initial state of charge difference, the step of determining the discharge capacity of the battery system based on the initial state of charge difference and the current state of charge difference of the battery system is performed. If the current state of charge difference is less than the initial state of charge difference, the minimum value among the individual cell health state values ​​is determined as the battery system health state value.

4. The estimation method according to claim 1, characterized in that, The estimation method further includes: Obtain the rated capacity of each individual cell, as well as the amount of capacity change and the amount of state of charge change between two state of charge value corrections; The individual cell health status value is obtained based on the rated capacity, the capacity change, and the state of charge change.

5. The estimation method according to claim 1, characterized in that, The estimation method further includes: Obtain the maximum voltage difference between the individual battery cells; The initial state of charge difference is obtained by looking up the table based on the maximum voltage difference.

6. A device for estimating the state of health of a battery system, characterized in that, The battery system includes multiple individual battery cells, and the estimation device includes: A state of charge correction unit is used to correct the state of charge value of each individual cell according to the current voltage of each individual cell, so as to obtain the current state of charge difference of the battery system. The discharge capacity determination unit is used to determine the discharge capacity of the battery system based on the initial state-of-charge difference and the current state-of-charge difference of the battery system. A battery health status value determination unit is used to determine the battery system health status value based on the minimum value between the discharge capacity and the individual cell health status value. The battery health status value determination unit is further configured to obtain the previous state-of-charge difference of the battery system, quotient the difference between the current state-of-charge difference and the previous state-of-charge difference with the current state-of-charge difference to obtain the weight of the discharge capacity, and determine the battery system health status value based on the minimum value among the discharge capacity, the weight, and the individual cell health status value; wherein, the discharge capacity is determined according to 1-( SOC- Calculated using SOC0, SOC0 is the difference in initial state of charge. SOC is the difference between the current state of charge and the current state of charge.

7. A device for estimating the state of health of a battery system, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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