Battery management method and related apparatus

Abstract

The application provides a battery management method and related device. The method comprises: obtaining initial differential voltages of each cell of a target battery pack after a preset current is applied to the target battery pack when the target battery pack is out of factory, and determining a standard resistance value of a copper bar between two adjacent battery groups of the target battery pack according to the initial differential voltages of each cell; collecting a current flowing through the target battery pack and a differential voltage of a cross-group cell at a current time; calculating a copper bar voltage of the copper bar connected between the two adjacent battery groups at the current time based on the standard resistance value of the copper bar between the two adjacent battery groups and the current; and subtracting the copper bar voltage from the differential voltage of the cross-group cell at the current time to obtain a cell voltage of the cross-group cell at the current time. The method can directly correct the differential voltage of the cross-group cell by using the copper bar voltage, thereby eliminating the sampling circuit for collecting the copper bar voltage and realizing the simplification of the battery management circuit.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery management method and related apparatus. Background Technology

[0002] Residential energy storage batteries, also known as home energy storage batteries, can store excess electrical energy generated by solar photovoltaic power generation systems or other renewable energy generation systems. This helps the power grid balance generation capacity and electricity demand, reducing electricity costs for residents and businesses. Furthermore, it serves as an emergency backup power source in the event of power outages due to major disasters or other factors, improving the reliability of power supply. During the charging and discharging process of residential energy storage batteries, excessively high or low charging and discharging voltages in some cells can lead to a decline in the overall performance of the battery. Therefore, real-time monitoring of the charging and discharging voltages of each cell is necessary.

[0003] Household energy storage battery packs typically consist of two battery groups, each containing eight cells. The two battery groups are connected by a copper busbar. To accurately collect the cell voltage of the battery pack and avoid inaccurate cell voltage collection caused by interference from the copper busbar, existing technologies typically use an 18-channel sampling circuit to collect the cell voltage and copper busbar voltage of the 16-cell battery pack separately. Although this method can accurately collect the cell voltage, the sampling circuit is large and not streamlined enough. Summary of the Invention

[0004] This invention provides a battery management method and related apparatus to solve the problem of excessively large battery sampling circuits.

[0005] In a first aspect, embodiments of the present invention provide a battery management method, comprising:

[0006] When the target battery pack leaves the factory, the initial differential voltage of each cell of the target battery pack is obtained after a preset current is applied to the target battery pack, and the standard resistance value of the copper busbar between two adjacent battery groups of the target battery pack is determined based on the initial differential voltage of each cell; the target battery pack includes at least two battery groups.

[0007] The current flowing through the target battery pack at the current moment and the differential voltage of the cross-group cells in the target battery pack are collected; the cross-group cells are cells whose differential voltage is calculated using the first electrode voltage of cells located in two adjacent battery groups; the first electrode is either the positive electrode or the negative electrode;

[0008] Based on the standard resistance of the copper busbar between two adjacent battery packs and the current, calculate the copper busbar voltage at the current moment for the copper busbar connecting the two adjacent battery packs.

[0009] For any cross-group cell, the cell voltage at the current moment is obtained by subtracting the corresponding copper bus voltage from the differential voltage of the cross-group cell at the current moment.

[0010] Secondly, embodiments of the present invention provide a battery management device, comprising:

[0011] A standard resistance value acquisition module is used to acquire the initial differential voltage of each cell after applying a preset current to the target battery pack when the target battery pack leaves the factory, and to determine the standard resistance value of the copper busbar between two adjacent battery groups of the target battery pack based on the initial differential voltage of each cell; the target battery pack includes at least two battery groups.

[0012] The differential voltage acquisition module is used to acquire the current flowing through the target battery pack at the current moment and the differential voltage of the cross-group cells in the target battery pack; the cross-group cells are cells whose differential voltage is calculated using the first electrode voltage of cells located in two adjacent battery groups; the first electrode is either the positive electrode or the negative electrode;

[0013] The copper busbar voltage acquisition module is used to calculate the copper busbar voltage of the copper busbar connecting the two adjacent battery packs at the current moment based on the standard resistance value of the copper busbar between the two adjacent battery packs and the current.

[0014] The battery management module is used to subtract the corresponding copper bus voltage from the differential voltage of any cross-group cell at the current moment to obtain the cell voltage of the cross-group cell at the current moment.

[0015] Thirdly, embodiments of the present invention provide a battery management system, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method as described in any possible implementation of the first aspect above.

[0016] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as described in any possible implementation of the first aspect above.

[0017] Fifthly, embodiments of the present invention provide a residential energy storage system, which includes a battery pack and a battery management system as described in the third aspect above.

[0018] This invention provides a battery management method and related apparatus. The method first acquires the initial differential voltage of each cell in the target battery pack after applying a preset current to the target battery pack at the factory. Based on the initial differential voltage of each cell, the standard resistance value of the copper busbar between two adjacent battery groups in the target battery pack is determined. During actual application of the battery pack, the differential voltage of the cross-group cells in the target battery pack is acquired at the current moment. The target battery pack includes at least two battery groups, and the cross-group cells are cells whose differential voltage is calculated using the first electrode voltage of adjacent cells located in the two battery groups. The first electrode is either the positive or negative electrode. Then, the copper busbar voltage connecting the two adjacent battery groups is acquired at the current moment. For any cross-group cell, the differential voltage of the cross-group cell at the current moment is subtracted from the corresponding copper busbar voltage to obtain the cell voltage of the cross-group cell at the current moment. The above method can calculate the copper busbar voltage by obtaining the standard resistance value of the copper busbar, and directly use the copper busbar voltage to correct the differential voltage of the cells in the cross group, thereby eliminating the sampling circuit for collecting the copper busbar voltage and simplifying the battery sampling circuit. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an application scenario diagram of the battery management method provided in the embodiments of the present invention;

[0021] Figure 2 This is a flowchart illustrating the implementation of the battery management method provided in this embodiment of the invention.

[0022] Figure 3 This is a schematic diagram of the battery management device provided in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the battery management system provided in an embodiment of the present invention. Detailed Implementation

[0024] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0026] Figure 1 This is an application scenario diagram of the battery management method provided in an embodiment of the present invention. For example... Figure 1 As shown, the target battery pack includes two battery groups, each containing eight cells. All cells are connected in series, and the two groups of cells are connected by a copper busbar.

[0027] To accurately obtain the battery voltage of each cell in a target battery pack, existing technologies acquire cell voltages using differential signal acquisition. This involves acquiring the negative electrode voltage of the preceding cell and the current cell from two adjacent cells, and calculating the difference between the two voltages to obtain the current cell's voltage. However, when the acquired differential voltage requires the negative electrode voltage of cells across the battery pack for calculation, inaccurate sampling occurs due to the cross-pack copper busbars. During battery pack charging, the sampled differential voltage of cells across the pack is too high, and during battery pack discharging, it is too low, thus reducing the accuracy of battery charge / discharge protection. Therefore, existing technologies often incorporate additional sampling circuits to acquire copper busbar voltages when acquiring cell voltages, using these copper busbar voltages to correct the differential voltage of cells across the pack. However, this results in a large, less streamlined sampling circuit that occupies significant space.

[0028] See Figure 2 The flowchart illustrating the implementation of the battery management method provided in this embodiment of the invention is described in detail below:

[0029] S101: When the target battery pack leaves the factory, the initial differential voltage of each cell of the target battery pack is obtained after a preset current is applied to the target battery pack, and the standard resistance value of the copper busbar between two adjacent battery groups of the target battery pack is determined according to the initial differential voltage of each cell; the target battery pack includes at least two battery groups.

[0030] The implementing entity in this embodiment can be a battery management system (BMS) for residential energy storage batteries, or a battery module management unit (BMU). This embodiment uses a BMS as an example to explain the battery management method provided in this application.

[0031] Specifically, when a battery pack leaves the factory, the internal resistance of each cell is usually the same. When a certain current is applied to the battery pack, the differential voltage of each cell should theoretically be the same. However, due to the presence of copper busbars, the differential voltage of cells in different groups often deviates from the cell voltages of other cells; this deviation is the copper busbar voltage. Therefore, the standard resistance value of the copper busbar can be calculated based on the initial differential voltage of each cell when each battery pack leaves the factory and stored in the BMS.

[0032] S102: Collect the current flowing through the target battery pack at the current moment and the differential voltage of the cross-group cells in the target battery pack; the cross-group cells are cells whose differential voltage is calculated using the first electrode voltage of cells located in two adjacent battery groups; the first electrode is either the positive electrode or the negative electrode.

[0033] Specifically, the BMS collects the differential voltage of each cell in the battery pack through a differential sampling circuit. The first terminal can be the negative terminal. When the battery pack includes two battery groups, each containing eight cells, the cell in the cross-group is the ninth cell from the positive terminal of the battery pack. The differential voltage of this cell is obtained by subtracting the negative terminal voltage of the eighth cell from the negative terminal voltage of the ninth cell. Since the eighth and ninth cells belong to two battery groups, and the negative terminal of the eighth cell and the positive terminal of the ninth cell are connected by a copper busbar, the voltage of the copper busbar needs to be subtracted when calculating the differential voltage of the ninth cell.

[0034] S103: Based on the standard resistance of the copper busbar between two adjacent battery packs and the current, calculate the copper busbar voltage at the current moment for the copper busbar connecting the two adjacent battery packs.

[0035] S104: For any cross-group cell, subtract the corresponding copper bus voltage from the differential voltage of the cross-group cell at the current moment to obtain the cell voltage of the cross-group cell at the current moment.

[0036] As can be seen from the above implementation method, the above method can calculate the copper bus voltage by obtaining the standard resistance value of the copper bus, and directly use the copper bus voltage to correct the differential voltage of the cross-group cells, thereby eliminating the sampling circuit for collecting the copper bus voltage, saving space, and realizing the simplification of the cell voltage sampling circuit.

[0037] In one possible implementation, the specific implementation process of S101 includes:

[0038] The difference between the initial differential voltage and the average cell voltage of the first cross-group cell is calculated. The average cell voltage is the average of the initial differential voltages of the other cells in the target battery pack, excluding the cross-group cells. The first cross-group cell can be any cross-group cell.

[0039] Divide the difference corresponding to the first cross-group cell by the preset current to obtain the standard resistance value of the copper busbar corresponding to the first cross-group cell.

[0040] Specifically, the standard resistance value of the copper busbar is obtained through the above method. During the subsequent operation of the battery pack, this standard resistance value is multiplied by the real-time current flowing through the battery pack to obtain the copper busbar voltage.

[0041] In one possible implementation, the specific implementation process of S103 includes:

[0042] Obtain the temperature of the copper busbar at the current moment;

[0043] For any copper busbar, the standard resistance of the copper busbar is corrected based on its current temperature and the temperature at which its standard resistance was tested; the corrected resistance is then multiplied by the current to obtain the copper busbar voltage at the current moment.

[0044] In this embodiment, the resistance of the copper busbar increases with temperature. In order to improve the accuracy of voltage detection across groups of cells, this embodiment can also correct the standard resistance of the copper busbar based on the temperature of the copper busbar at the current moment and the temperature when the standard resistance of the copper busbar was tested at the factory.

[0045] Specifically, the BMS can subtract the temperature at which the standard resistance value of the copper busbar was tested from the temperature at the current moment to obtain the temperature difference, determine the corresponding first compensation resistor based on the temperature difference, and add the first compensation resistor to the standard resistance value to obtain the corrected copper busbar resistance.

[0046] The temperature difference is positively correlated with the first compensation resistor, and the coefficient between the temperature difference and the first compensation resistor can be obtained through actual experiments.

[0047] In one possible implementation, another implementation process of S103 may include:

[0048] Get the current ambient temperature;

[0049] For any copper busbar, the standard resistance value of the copper busbar is corrected based on the current ambient temperature and the ambient temperature when the standard resistance value of the copper busbar was tested; and the corrected resistance of the copper busbar is multiplied by the current to obtain the copper busbar voltage at the current moment.

[0050] Specifically, the BMS can subtract the ambient temperature when testing the standard resistance of the copper busbar from the current ambient temperature to obtain the ambient temperature difference. If the ambient temperature difference is greater than the first preset temperature threshold, the corresponding second compensation resistor is determined based on the ambient temperature difference. The second compensation resistor is added to the standard resistance value to obtain the corrected copper busbar resistance.

[0051] Among them, the ambient temperature difference is positively correlated with the second compensation resistor, and the coefficient between the ambient temperature difference and the second compensation resistor can be obtained through actual experiments.

[0052] In one possible implementation, the battery pack includes two battery packs;

[0053] The battery management method provided in this embodiment also includes:

[0054] S201: Obtain the voltage between the positive and negative terminals of the battery pack at the current moment, and use the voltage between the positive and negative terminals of the battery pack as the battery voltage;

[0055] S202: Sum the differential voltages of all cells in the battery pack at the current moment to obtain the cumulative battery voltage;

[0056] S203: Calculate the difference between the current battery accumulated voltage and the current battery voltage to obtain the voltage difference value;

[0057] S204: Based on the voltage difference, determine whether there is a fault in the copper busbar between the two battery packs.

[0058] In this embodiment, during the charging and discharging process of the battery pack, when the connection of the copper busbar becomes loose, the resistance of the copper busbar increases, and the temperature of the copper busbar rises, which may lead to thermal runaway of the battery pack. In order to avoid thermal runaway of the battery pack, this embodiment can determine the current resistance of the copper busbar by calculating the difference between the battery voltage and the battery cumulative voltage. Based on the current resistance of the copper busbar, it can be determined whether there is a loose connection at the copper busbar. If it is determined that the copper busbar is loose, an alarm message for the loose copper busbar is generated and displayed to prompt the user to deal with the fault in time.

[0059] In one possible implementation, the specific implementation process of S204 includes:

[0060] If the voltage difference is greater than the first voltage threshold, the copper busbar is determined to be faulty, and a fault alarm message is generated.

[0061] In one possible implementation, another step in S204 includes:

[0062] Divide the voltage difference by the current at the current moment to obtain the current resistance of the copper busbar;

[0063] The resistance difference is obtained by subtracting the current resistance value of the copper busbar from the standard resistance value of the copper busbar when the battery pack leaves the factory.

[0064] If the resistance difference is greater than a first preset threshold, a copper busbar fault alarm message is generated.

[0065] Specifically, existing technologies for detecting copper busbars typically use temperature sensors to collect the temperature of the copper busbar. When the temperature of the copper busbar exceeds a certain threshold, it indicates a possible loose connection fault. However, this method requires an additional temperature sensor to detect the copper busbar temperature. Furthermore, using temperature to determine looseness requires waiting for the temperature to rise during circuit operation and form a temperature difference on the copper busbar that can be detected by the temperature sensor, resulting in hysteresis. The method provided in this embodiment not only achieves copper busbar fault detection but also eliminates the need for additional components. It utilizes only circuit sampling devices to achieve copper busbar fault detection, further simplifying the battery sampling circuit and eliminating detection hysteresis.

[0066] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0067] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0068] Figure 4 A schematic diagram of the battery management device provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0069] like Figure 4 As shown, the battery management device 100 includes:

[0070] The standard resistance value acquisition module 110 is used to acquire the initial differential voltage of each cell after applying a preset current to the target battery pack when the target battery pack leaves the factory, and to determine the standard resistance value of the copper busbar between two adjacent battery groups of the target battery pack based on the initial differential voltage of each cell; the target battery pack includes at least two battery groups.

[0071] The differential voltage acquisition module 120 is used to acquire the current flowing through the target battery pack at the current moment and the differential voltage of the cross-group cells in the target battery pack; the cross-group cells are cells whose differential voltage is calculated using the first electrode voltage of cells located in two adjacent battery groups; the first electrode is either the positive electrode or the negative electrode;

[0072] The copper busbar voltage acquisition module 130 is used to calculate the copper busbar voltage of the copper busbar connecting the two adjacent battery packs at the current moment based on the standard resistance value of the copper busbar between the two adjacent battery packs and the current.

[0073] The battery management module 140 is used to subtract the corresponding copper bus voltage from the differential voltage of any cross-group cell at the current moment to obtain the cell voltage of the cross-group cell at the current moment.

[0074] In one possible implementation, the standard resistance value acquisition module 110 is used for:

[0075] The difference between the initial differential voltage and the average cell voltage of the first cross-group cell is calculated. The average cell voltage is the average of the initial differential voltages of the other cells in the target battery pack, excluding the cross-group cells. The first cross-group cell can be any cross-group cell.

[0076] Divide the difference corresponding to the first cross-group cell by the preset current to obtain the standard resistance value of the copper busbar corresponding to the first cross-group cell.

[0077] In one possible implementation, the copper bus voltage acquisition module 130 includes:

[0078] Obtain the temperature of the copper busbar at the current moment;

[0079] For any copper busbar, the standard resistance of the copper busbar is corrected based on its current temperature and the temperature at which its standard resistance was tested; the corrected resistance is then multiplied by the current to obtain the copper busbar voltage at the current moment.

[0080] In one possible implementation, the battery management device 100 provided in this embodiment further includes a fault detection module, comprising:

[0081] A battery voltage acquisition unit is used to acquire the voltage between the positive and negative terminals of the battery pack at the current moment, and to use the voltage between the positive and negative terminals of the battery pack as the battery voltage.

[0082] The battery cumulative voltage acquisition unit is used to sum the differential voltages of all cells in the battery pack at the current moment to obtain the battery cumulative voltage.

[0083] The voltage difference calculation unit is used to calculate the voltage difference by subtracting the battery's accumulated voltage and the battery voltage at the current moment.

[0084] The fault detection unit is used to determine whether there is a fault in the copper busbar between the two battery packs based on the voltage difference.

[0085] In one possible implementation, the fault detection unit includes:

[0086] If the voltage difference is greater than the first voltage threshold, the copper busbar is determined to be faulty, and a fault alarm message is generated.

[0087] In one possible implementation, the fault detection unit includes:

[0088] Divide the voltage difference by the current at the current moment to obtain the current resistance of the copper busbar;

[0089] The resistance difference is obtained by subtracting the current resistance value of the copper busbar from the standard resistance value of the copper busbar when the battery pack leaves the factory.

[0090] If the resistance difference is greater than a first preset threshold, a copper busbar fault alarm message is generated.

[0091] Figure 4 This is a schematic diagram of the battery management system provided in an embodiment of the present invention. Figure 4 As shown, the battery management system 4 of this embodiment includes a processor 40 and a memory 41. The memory 41 stores a computer program 42, and the processor 40 calls and runs the computer program 42 stored in the memory 41 to execute the steps described in the various battery management method embodiments above, for example... Figure 2 Steps S101 to S104 are shown. Alternatively, the processor 40 is used to call and run the computer program 42 stored in the memory 41 to implement the functions of each module / unit in the above-described device embodiments, for example... Figure 3 The functions of modules 110 to 140 are shown.

[0092] For example, the computer program 42 can be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 42 in the battery management system 4.

[0093] The battery management system 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art will understand that... Figure 4 This is merely an example of the battery management system 4 and does not constitute a limitation on the battery management system 4. It may include more or fewer components than shown, or combine certain components, or different components. For example, the battery management system may also include input / output devices, network access devices, buses, etc.

[0094] The processor 40 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0095] The memory 41 can be an internal storage unit of the battery management system 4, such as a hard disk or memory of the battery management system 4. The memory 41 can also be an external storage device of the battery management system 4, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the battery management system 4. Furthermore, the memory 41 can include both internal storage units and external storage devices of the battery management system 4. The memory 41 is used to store the computer program and other programs and data required by the battery management system. The memory 41 can also be used to temporarily store data that has been output or will be output.

[0096] In one possible implementation, this embodiment provides a residential energy storage system including a battery pack and a battery management system 4.

[0097] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0099] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0100] In the embodiments provided by this invention, it should be understood that the disclosed device / battery management system and method can be implemented in other ways. For example, the device / battery management system embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0101] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0102] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0103] If the integrated module / 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, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various battery management method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0104] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A battery management method, characterized by, The method comprises the following steps: When a target battery pack is manufactured, initial differential voltages of each cell of the target battery pack are obtained after a preset current is applied to the target battery pack, and a standard resistance value of a copper bar between two adjacent battery groups of the target battery pack is determined according to the initial differential voltages of each cell; the target battery pack comprises at least two battery groups; A current flowing through the target battery pack at a current time and a differential voltage of a cross-group cell in the target battery pack are collected; the cross-group cell is a cell whose first pole voltage is calculated according to the differential voltage of adjacent cells located in two battery groups; the first pole is any one of a positive pole and a negative pole; A copper bar voltage of the copper bar connected between the two adjacent battery groups at the current time is calculated based on the standard resistance value of the copper bar between the two adjacent battery groups and the current; For any cross-group cell, a cell voltage of the cross-group cell at the current time is obtained by subtracting the corresponding copper bar voltage from the differential voltage of the cross-group cell at the current time; The standard resistance value of the copper bar between the two adjacent battery groups of the target battery pack is determined according to the initial differential voltages of each cell, which comprises: A difference value is obtained by subtracting a cell average voltage from an initial differential voltage of a first cross-group cell; the cell average voltage is a mean value of the initial differential voltages of other cells in the target battery pack except the cross-group cell; the first cross-group cell is any cross-group cell; The standard resistance value of the copper bar corresponding to the first cross-group cell is obtained by dividing the difference value corresponding to the first cross-group cell by the preset current; The copper bar voltage of the copper bar connected between the two adjacent battery groups at the current time is calculated based on the standard resistance value of the copper bar between the two adjacent battery groups and the current, which comprises: A temperature of the copper bar at the current time is obtained; For any copper bar, the standard resistance value of the copper bar is corrected according to the temperature of the copper bar at the current time and the temperature when the standard resistance value of the copper bar is tested; and the copper bar voltage of the copper bar at the current time is obtained by multiplying the corrected resistance of the copper bar by the current.

2. The battery management method of claim 1, wherein, The battery pack comprises two battery groups; The method further comprises: A voltage between positive and negative poles of the battery pack at a current time is obtained, and the voltage between the positive and negative poles of the battery pack is taken as a battery voltage; A differential voltage of all cells in the battery pack at the current time is summed up to obtain a battery cumulative voltage; A voltage difference value is obtained by subtracting the battery cumulative voltage at the current time from the battery voltage; Whether a copper bar between the two battery groups has a fault is determined based on the voltage difference value.

3. The battery management method of claim 2, wherein, Whether the copper bar between the two battery groups has a fault is determined based on the voltage difference value, which comprises: If the voltage difference value is greater than a first voltage threshold, it is determined that the copper bar has a fault, and a fault alarm information is generated.

4. The battery management method of claim 2, wherein, Whether the copper bar between the two battery groups has a fault is determined based on the voltage difference value, which comprises: A current resistance value of the copper bar is obtained by dividing the voltage difference value by the current at the current time; A resistance difference value is obtained by subtracting the standard resistance value of the copper bar from the current resistance value of the copper bar; If the resistance difference value is greater than a first preset threshold, a copper bar fault alarm information is generated.

5. A battery management device, characterized by, The method comprises the following steps: The standard resistance acquisition module is configured to acquire initial differential voltages of each cell after a preset current is applied to the target battery pack when the target battery pack is manufactured, and determine a standard resistance of a copper bar between two adjacent battery groups of the target battery pack according to the initial differential voltages of each cell. The differential voltage acquisition module is configured to acquire a current flowing through the target battery pack and a differential voltage of a cross-group cell in the target battery pack at a current time. The copper bar voltage acquisition module is configured to calculate a copper bar voltage of a copper bar connected between two adjacent battery groups at the current time based on the standard resistance of the copper bar between the two adjacent battery groups and the current. The battery management module is configured to, for any cross-group cell, subtract the corresponding copper bar voltage from the differential voltage of the cross-group cell at the current time to obtain a cell voltage of the cross-group cell at the current time. The standard resistance acquisition module includes: The first cross-group cell is any cross-group cell. The standard resistance of the copper bar corresponding to the first cross-group cell is obtained by dividing the difference value corresponding to the first cross-group cell by the preset current. The copper bar voltage acquisition module includes: The temperature of the copper bar at the current time is acquired. For any copper bar, the standard resistance of the copper bar is corrected according to the temperature of the copper bar at the current time and the temperature when the standard resistance of the copper bar is tested, and the corrected resistance of the copper bar is multiplied by the current to obtain the copper bar voltage of the copper bar at the current time.

6. A battery management system, characterized by, The computer program is executed by the processor to implement the steps of the battery management method according to any one of claims 1 to 4.

7. A computer-readable storage medium storing a computer program, wherein the computer program comprises the following steps of: receiving a request for a resource from a client; determining whether the client is authorized to access the resource; and if the client is authorized to access the resource, providing the resource to the client. The computer program is executed by the processor to implement the steps of the battery management method according to any one of claims 1 to 4.

8. A home energy storage system characterized by, The battery management system according to claim 6. The battery management system according to claim 6.

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