Apparatus for diagnosing state of battery and method thereof

Abstract

An apparatus for diagnosing a state of a battery and a method thereof, which can accurately diagnose the state of the battery and the state of each cell constituting the battery by: monitoring a charging current of the battery to determine a diagnosis time interval at which a preset current change value is maintained; determining a first voltage and a second voltage within the diagnostic time interval; determining the time required for each cell voltage of each cell of the battery to reach a second voltage from a first voltage within the diagnosis time interval; the state of the battery is diagnosed based on the time corresponding to each cell.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of Korean Patent Application No. 10-2024-0154580, filed on November 4, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to a technique for diagnosing the condition of batteries installed in electric vehicles with high accuracy. Background Technology

[0004] In general, electric vehicles are vehicles powered by electricity and equipped with batteries that include multiple battery cells that store electrical energy. These battery cells convert chemical energy into electrical energy to supply power (discharging), or convert electrical energy supplied from an external source into chemical energy for storage (charging).

[0005] Since electric vehicles are powered by electrical energy stored in batteries, their performance is significantly affected by battery performance. Therefore, to improve the performance of electric vehicles, battery management is necessary to maximize performance.

[0006] In recent years, with the use of high-performance battery cells to improve vehicle power and the increasing number of battery cells, battery management has become increasingly necessary. This battery management is typically performed by a battery management system (BMS).

[0007] The battery management system measures cell status information (including voltage, current, temperature, etc.) from the battery cells in the battery module located in the electric vehicle, manages the battery cells using the cell status information and option values ​​for controlling the battery cells, and performs cell balancing to maintain balance between the battery cells.

[0008] Cell balancing is a control operation in a battery management system used to equalize the voltage or charge level of battery cells. Even if the battery cells in a battery module are manufactured under the same conditions and environment, each cell may differ in its electrical characteristics. Similarly, even if the battery cells in a battery module are installed and operated in an electric vehicle, each cell may still exhibit differences in its electrical characteristics.

[0009] Due to these differences in electrical characteristics, even if battery cells are charged and discharged with the same current, voltage imbalance or remaining charge imbalance may occur between interconnected battery cells. This voltage imbalance or remaining charge imbalance between battery cells may reduce the usable voltage range of the battery cells or shorten the charge and discharge cycles.

[0010] Recently, electric vehicles have been frequently experiencing fires while charging their batteries. This is caused by abnormal battery conditions. To prevent such fires, technology capable of accurately diagnosing the condition of the batteries installed in electric vehicles is needed.

[0011] In some cases, in order to diagnose the state of a battery, the voltage change of the battery is monitored during the first transition interval (or time interval) from closed-circuit voltage (CCV) to open-circuit voltage (OCV) and the second transition interval (or time interval) from OCV to CCV, and the state of the battery is diagnosed based on the monitoring results.

[0012] However, because battery voltage changes are monitored only during the very short first and second transition intervals, it is impossible to adequately monitor battery voltage changes. Therefore, it may not be possible to diagnose battery status with high accuracy.

[0013] The matters described in this background section are intended to facilitate an understanding of the background of this application and may include matters not known to those skilled in the art. Summary of the Invention

[0014] This application is made to address the problems mentioned above, while retaining the advantages achieved by existing technologies.

[0015] One aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery but also the state of each cell constituting the battery by: monitoring the charging current of the battery to determine or detect a current range (i.e., a diagnostic time interval) that maintains a preset current change value; determining a first voltage and a second voltage within the current range; determining or detecting the time required for the voltage of each cell of the battery to reach the second voltage from the first voltage within the current range; and diagnosing the state of the battery based on the time corresponding to each cell.

[0016] Another aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery but also the state of each cell constituting the battery by: monitoring the charging current of the battery to detect or determine a current range that maintains a preset current change value; determining a first voltage and a second voltage within the current range; detecting or determining the time required for the voltage of each cell in a plurality of cells of the battery to rise from the first voltage to the second voltage within the current range, and determining the standard deviation (σ) of the time corresponding to the plurality of cells; and diagnosing the state of the battery based on the number of cells contained within a threshold range (i.e., a threshold range) (e.g., less than -2σ and greater than 2σ).

[0017] Another aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery, but also the state of each cell constituting the battery by: monitoring the charging current of the battery to detect or determine at least one current range (or multiple current ranges) that maintains a preset current change value; determining a first voltage and a second voltage within each current range; detecting or determining the time required for the voltage of each cell within each current range to reach the second voltage from the first voltage; and diagnosing the state of the battery based on the time corresponding to each cell within each current range.

[0018] Another aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery but also the state of each cell constituting the battery by: monitoring the charging current of the battery to detect or determine at least one current interval (or multiple current intervals) that maintains a preset current change value; determining a first voltage and a second voltage within each current interval; detecting or determining the time required for the voltage of each cell within each current interval to reach the second voltage from the first voltage, and determining the standard deviation (σ) of the time corresponding to multiple cells of the battery within each current interval; and diagnosing the state of the battery based on the number of cells included in a threshold interval (e.g., less than -2σ and greater than 2σ).

[0019] Another aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery, but also the state of each of the plurality of cells constituting the battery by: monitoring the charging current of the battery to detect or determine a current range that maintains a preset current change value; determining the maximum value (i.e., the highest value) among the minimum voltages of the plurality of cells within the current range as a first voltage of the current range; determining the minimum value (i.e., the lowest value) among the maximum voltages of the plurality of cells within the current range as a second voltage of the current range; detecting or determining the time required for the voltage of each cell of the battery within the current range to reach the second voltage from the first voltage; and diagnosing the state of the battery based on the time corresponding to each cell.

[0020] Another aspect of this application provides an apparatus and method for diagnosing the state of a battery, which can accurately diagnose not only the state of the battery but also the state of each cell constituting the battery by: monitoring the charging current of the battery to detect or determine a current range that maintains a preset current change value; determining a first voltage and a second voltage as a voltage range of the current range; dividing the voltage range into multiple voltage intervals (i.e., dividing into multiple voltage intervals); determining a minimum voltage and a maximum voltage within each voltage interval; detecting or determining the time required for the voltage of each cell of the battery to reach the maximum voltage from the minimum voltage within each voltage interval; and diagnosing the state of the battery based on the time corresponding to each cell.

[0021] The technical problems to be solved by this application are not limited to those mentioned above, and those skilled in the art should clearly understand any other technical problems not mentioned herein through the following description. Furthermore, it will be readily understood that the objectives and advantages of this application can be achieved by the means recited in the claims and combinations thereof.

[0022] According to one aspect of this application, an apparatus for diagnosing the state of a battery includes a current sensor for detecting or determining the charging current of the battery, a voltage sensor for detecting or determining the voltage of the battery, and a controller. The controller monitors the charging current of the battery to detect or determine a current range that maintains a preset current change value, determines a first voltage and a second voltage as a voltage range within the current range, detects or determines the time required for the voltage of each of a plurality of cells in the battery to reach the second voltage from the first voltage within the current range, and diagnoses the state of the battery based on the time corresponding to each cell.

[0023] According to the implementation scheme, the controller can detect or determine the maximum and minimum voltage of each unit within the current range, determine the maximum or highest value among the minimum voltages of the units as the first voltage of the current range, and determine the minimum or lowest value among the maximum voltages of the units as the second voltage of the current range.

[0024] According to the implementation scheme, the controller can determine the standard deviation of time corresponding to the cell and diagnose the state of the battery based on the standard deviation.

[0025] According to the implementation scheme, the controller can detect or determine at least one current range, determine a first voltage and a second voltage within each current range of at least one current range, detect or determine the time required for the voltage of each cell to reach the second voltage from the first voltage within each current range of at least one current range, and diagnose the state of the battery based on the time corresponding to each cell within each current range of at least one current range.

[0026] According to the implementation scheme, the controller can determine the standard deviation of the time corresponding to multiple units within each current interval, and diagnose the state of the battery based on the standard deviation of each current interval.

[0027] According to the implementation scheme, the controller can divide the voltage range into multiple voltage intervals, detect or determine the time required for each cell voltage to reach the maximum voltage from the minimum voltage in each voltage interval (i.e., voltage interval time), and diagnose the battery status based on the time corresponding to each cell in each voltage interval.

[0028] According to the implementation scheme, the controller can determine the standard deviation of the time corresponding to multiple units within each voltage range, and diagnose the state of the battery based on the standard deviation of each voltage range.

[0029] According to the implementation scheme, the controller can monitor the battery charging current in all intervals (i.e., time intervals) except for the state transition interval between the closed-circuit voltage (CCV) and the open-circuit voltage (OCV).

[0030] According to the implementation scheme, the controller can detect or determine the current range (i.e., the diagnostic time interval) where the current change value is 0 (zero).

[0031] According to another aspect of this application, a method for diagnosing the state of a battery includes: a controller detecting or determining a current range that maintains a preset current change value by monitoring the charging current of the battery; the controller determining a first voltage and a second voltage as a voltage range of the current range; the controller detecting or determining the time required for the voltage of each cell of a plurality of cells in the battery to reach the second voltage from the first voltage within the current range; and the controller diagnosing the state of the battery based on the time corresponding to each cell.

[0032] According to the implementation scheme, determining the first voltage and the second voltage may include: detecting or determining the maximum voltage and minimum voltage of each unit within the current range; determining the maximum value among the minimum voltages of the plurality of units as the first voltage of the current range; and determining the minimum value among the maximum voltages of the units as the second voltage of the current range.

[0033] According to the implementation scheme, diagnosing the state of the battery may include: determining the standard deviation of time corresponding to the plurality of cells; and diagnosing the state of the battery based on the standard deviation.

[0034] According to the implementation plan, diagnosing the state of a battery may include: diagnosing the state of the battery based on detecting or determining multiple current ranges, and diagnosing the state of the battery based on the time corresponding to each cell within each of the multiple current ranges (i.e., within each of the multiple diagnostic time intervals).

[0035] According to the implementation plan, diagnosing the state of the battery may include: determining the standard deviation of the time corresponding to each cell within each current range; and diagnosing the state of the battery based on the standard deviation of each current range.

[0036] According to the implementation plan, diagnosing the state of a battery may include: dividing the voltage range into multiple voltage intervals, and diagnosing the state of the battery based on the time corresponding to each cell within each voltage interval (i.e., voltage interval time).

[0037] According to the implementation scheme, diagnosing the state of the battery may include: determining the standard deviation of the time corresponding to the plurality of cells within each voltage range; and diagnosing the state of the battery based on the standard deviation of each voltage range.

[0038] According to the implementation plan, detecting or determining the current range may include monitoring the battery charging current in all ranges (i.e., all time intervals) except for the state transition range between the closed-circuit voltage (CCV) and the open-circuit voltage (OCV).

[0039] According to the implementation plan, detecting or determining a current range may include: detecting or determining the time interval of a constant current range with a current change value of 0 (zero) as the current range (i.e., the diagnostic time interval). Attached Figure Description

[0040] The above and other objects, features and advantages of this application should become more apparent from the following detailed description taken in conjunction with the accompanying drawings:

[0041] Figure 1 This is a schematic diagram illustrating an apparatus for diagnosing the state of a battery according to an embodiment of this application;

[0042] Figure 2 This is a schematic diagram illustrating an example of a range of battery charging current monitored by a controller in an apparatus for diagnosing the state of a battery according to an embodiment of this application.

[0043] Figure 3 This is a schematic diagram illustrating an example of a current range detected by a controller in an apparatus for diagnosing the state of a battery according to an embodiment of this application;

[0044] Figure 4AThis is a schematic diagram showing the voltage of each cell constituting the battery within the current range C1;

[0045] Figure 4B This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C2;

[0046] Figure 4C This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C3;

[0047] Figure 4D This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C4;

[0048] Figure 4E This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C5;

[0049] Figure 4F This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C6;

[0050] Figure 5 This is a schematic diagram illustrating the operation of a controller provided in a device for diagnosing the state of a battery according to an embodiment of this application, which determines the minimum voltage (i.e., the first voltage) and the maximum voltage (i.e., the second voltage) within a current range C1.

[0051] Figure 6 This is a schematic diagram showing the result of a controller provided in a device for diagnosing the state of a battery according to an embodiment of this application dividing the voltage range of current interval C1 into multiple voltage intervals.

[0052] Figure 7 This is a schematic diagram illustrating an example of the operation of a controller installed in a device for diagnosing the state of a battery according to an embodiment of this application, which detects the time-varying values ​​of the voltage of each cell.

[0053] Figure 8A This is a schematic diagram showing the time required for the voltage of each cell within the current range C1 to rise from the minimum voltage to the maximum voltage.

[0054] Figure 8B This is a schematic diagram showing the time required for the voltage of each cell within the current range C2 to reach the maximum voltage from the minimum voltage.

[0055] Figure 8C This is a schematic diagram showing the time required for the voltage of each cell within the current range C3 to rise from the minimum voltage to the maximum voltage.

[0056] Figure 8D This is a schematic diagram showing the time required for the voltage of each cell within the current range C4 to reach the maximum voltage from the minimum voltage.

[0057] Figure 8E This is a schematic diagram showing the time required for the voltage of each cell to reach the maximum voltage from the minimum voltage within the current range C5;

[0058] Figure 8F This is a schematic diagram showing the time required for the voltage of each cell within the current range C6 to reach the maximum voltage from the minimum voltage.

[0059] Figure 9 This is a schematic diagram showing the graded units of a controller installed in an apparatus for diagnosing the state of a battery according to an embodiment of this application;

[0060] Figure 10 This is a flowchart illustrating a method for diagnosing the state of a battery according to an embodiment of this application;

[0061] Figure 11 This is a block diagram illustrating a computational system for performing a method for diagnosing the state of a battery according to an embodiment of this application. Detailed Implementation

[0062] In the following, some embodiments of this application will be described in detail with reference to the accompanying drawings. When adding reference numerals to components in each drawing, it should be noted that even if the same or equivalent components are shown in other drawings, the components are represented by the same reference numerals. Furthermore, in describing embodiments of this application, detailed descriptions of relevant known configurations or functions will be omitted when it is determined that such configurations or functions interfere with the understanding of the embodiments of this application.

[0063] Furthermore, in describing the components of this application, terms such as first, second, A, B, (a), and (b) may be used. These terms are provided merely to distinguish elements from other elements, and the nature, order, sequence, and number of elements are not limited by these terms. Moreover, unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Terms defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted as having an imaginary or overly formal meaning, unless expressly defined in the specification of this application. When components, controllers, devices, elements, equipment, etc., of this application are described as having a purpose or performing an operation or function, such components, controllers, devices, elements, equipment, etc., shall be considered herein as "configured" to satisfy that purpose or perform that operation or function. Each component, controller, device, element, equipment, etc., may be implemented independently or may include a processor and memory (e.g., a non-transitory computer-readable medium) as part of a device.

[0064] Figure 1 This is a schematic diagram illustrating an apparatus for diagnosing the state of a battery according to an embodiment of this application.

[0065] like Figure 1 As shown, the device 100 for diagnosing the state of a battery according to an embodiment of this application may include a storage device 10, a current sensor 20, a voltage sensor 30, a display 40, and a controller 50. In this case, depending on the implementation of the device 100 for diagnosing the state of a battery according to an embodiment of this application, the components may be combined to form a single unit, or some components may be omitted. Furthermore, the device 100 for diagnosing the state of a battery may be installed in a vehicle, on a cloud server providing diagnostic services for multiple vehicles, or on a portable diagnostic device provided by a repair shop.

[0066] Regarding each component, firstly, the storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect current changes within a current range (i.e., time intervals, which may also be referred to herein as diagnostic time intervals) that remain within a preset current change value; determining the minimum voltage (i.e., the first voltage) and the maximum voltage (i.e., the second voltage) within the current range; detecting the time required for each cell voltage of the battery 200 to reach the maximum voltage from the minimum voltage within the current range; and diagnosing the state of the battery 200 based on the time corresponding to each cell. For example, the battery 200, which is a high-voltage battery installed in an electric vehicle, may include multiple cells.

[0067] The storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect a current range that maintains a preset current change value; determining the minimum and maximum voltages within the current range; detecting the time required for each cell voltage of the battery to reach the maximum voltage from the minimum voltage within the current range; determining the standard deviation (σ) of the time corresponding to each cell; and diagnosing the state of the battery 200 based on the number of cells included in a threshold range. For example, the threshold range may include ranges less than -2σ and ranges greater than 2σ on a normal distribution.

[0068] The storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect at least one current range that maintains a preset current change value; determining the minimum and maximum voltages within each current range; detecting the time required for the voltage of each cell of the battery 200 to reach the maximum voltage from the minimum voltage within each current range; and diagnosing the state of the battery 200 based on the time corresponding to each cell within each current range.

[0069] The storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect at least one current interval that maintains a preset current change value; determining the minimum and maximum voltages within each current interval; detecting the time required for the voltage of each cell of the battery 200 to reach the maximum voltage from the minimum voltage within each current interval; determining the standard deviation (σ) of the time corresponding to each cell within each current interval; and diagnosing the state of the battery 200 based on the number of cells contained within a threshold interval (e.g., less than -2σ and greater than 2σ).

[0070] The storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect a current range that maintains a preset current change value; determining the maximum value among the minimum voltages of each cell within the current range as the minimum voltage of the current range; determining the minimum value among the maximum voltages of each cell within the current range as the maximum voltage of the current range; detecting the time required for the voltage of each cell of the battery 200 to reach the maximum voltage from the minimum voltage within the current range; and diagnosing the state of the battery 200 based on the time corresponding to each cell.

[0071] The storage device 10 can store various logics, algorithms, and programs required for the following processes: monitoring the charging current of the battery 200 to detect a current range that maintains a preset current change value; determining the minimum and maximum voltages of the voltage range that serves as the current range; dividing the voltage range into multiple voltage ranges; determining the minimum and maximum voltages within each voltage range; detecting the time required for the voltage of each cell of the battery 200 to reach the maximum voltage from the minimum voltage within each voltage range; and diagnosing the state of the battery 200 based on the time corresponding to each cell.

[0072] The current sensor 20 can detect the charging current of the battery 200.

[0073] Voltage sensor 30 can detect the internal voltage of the battery.

[0074] The display 40 can show the diagnostic results of the controller 50.

[0075] The controller 50 can be electrically connected to each component and can perform overall control, causing each component to perform its function. The controller 50 can be implemented in hardware or software, or a combination of hardware and software. For example, the controller 50 can be implemented as a microprocessor, but is not limited thereto.

[0076] The controller 50 can monitor the charging current of the battery 200 to detect the current range that maintains a preset current change value, determine the minimum and maximum voltages within the current range, detect the time required for the voltage of each cell of the battery 200 to reach the maximum voltage from the minimum voltage within the current range, and diagnose the state of the battery 200 based on the time corresponding to each cell.

[0077] In the following text, refer to Figures 2 to 9 Describe the operation of controller 50.

[0078] Figure 2 This is a schematic diagram illustrating an example of a range of battery charging current monitored by a controller in an apparatus for diagnosing the state of a battery according to an embodiment of this application.

[0079] exist Figure 2 In the figure, reference numeral 210 indicates the interval or time interval in which the transition from closed-circuit voltage (CCV) to open-circuit voltage (OCV) occurs, and reference numeral 220 indicates the interval or time interval in which the transition from OCV to CCV occurs. Reference numerals 210 and 220 correspond to the monitoring intervals used in related technologies. It can be understood that the interval or time interval indicated by reference numeral 230 is the monitoring interval used in this application, which is much wider than the interval or time interval indicated by reference numerals 210 and 220. Therefore, according to the embodiment, the accuracy of diagnosing the state of battery 200 can be improved.

[0080] Figure 3 This is a schematic diagram illustrating an example of a current range detected by a controller in an apparatus for diagnosing the state of a battery according to an embodiment of this application.

[0081] like Figure 3 As shown, controller 50 detects intervals C1, C2, C3, C4, C5, and C6 as current intervals that maintain preset current change values ​​(e.g., diagnostic time intervals). In this case, the current change value can be set to a range (e.g., 0mA to 10mA). Therefore, the current interval can include a constant current interval with a current change value of "0" (i.e., the current remains constant), and a current interval with a slope within a specified range (e.g., below 0.05) (i.e., an almost constant current interval).

[0082] Figure 4A This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C1. Figure 4B This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C2. Figure 4C This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C3. Figure 4D This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C4. Figure 4E This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C5. Figure 4F This is a schematic diagram showing the voltage of each cell constituting the battery within the current range C6.

[0083] Figure 5 This is a schematic diagram illustrating the operation of a controller installed in a device for diagnosing the state of a battery according to an embodiment of this application, which determines the minimum and maximum voltages within a current range C1.

[0084] like Figure 5 As shown, the controller 50 can monitor the voltage of all cells constituting the battery 200 within the current range C1 to detect the maximum and minimum voltage of each cell. Furthermore, the controller 50 can determine the highest or maximum value 510 of the minimum voltage of each cell as the minimum voltage of the current range C1 (e.g., 3620mV), and can determine the lowest or minimum value 520 of the maximum voltage of each cell as the maximum voltage of the current range C1 (e.g., 3715mV).

[0085] For example, when the minimum voltage of the first unit in the current range C1 is a1 and the maximum voltage is b1, the minimum voltage of the second unit is a2 and the maximum voltage is b2, and the minimum voltage of the third unit is a3 and the maximum voltage is b3, and a1 < a2 < a3 and b1 < b2 < b3 are satisfied, the controller 50 can determine the minimum voltage of the current range C1 as a3 and the maximum voltage of the current range C1 as b1.

[0086] For reference, the minimum voltage within current range C2 is 3775mV and the maximum voltage is 3965mV. The minimum voltage within current range C3 is 3975mV and the maximum voltage is 3981mV. The minimum voltage within current range C4 is 4007mV and the maximum voltage is 4016mV. The minimum voltage within current range C5 is 4038mV and the maximum voltage is 4051mV. The minimum voltage within current range C6 is 4073mV and the maximum voltage is 4116mV.

[0087] Figure 6 This is a schematic diagram showing the result of a controller provided in an apparatus for diagnosing the state of a battery according to an embodiment of this application dividing the voltage range of current interval C1 into multiple voltage intervals.

[0088] like Figure 6As shown, for example, controller 50 can divide the voltage range of current interval C1 (3620mV to 3715mV) into a first voltage interval 610, a second voltage interval 620, and a third voltage interval 630. In this case, considering the error of voltage sensor 30, controller 50 can divide the voltage range of current interval C1 (3620mV to 3715mV) into 5mV intervals. In this case, the voltage range of current interval C1 can be divided into a total of 19 voltage intervals.

[0089] For example, the first voltage range can be 3620mV to 3625mV, the second voltage range can be 3625mV to 3630mV, and the third voltage range can be 3630mV to 3635mV. Therefore, the controller 50 can determine the minimum voltage of the first voltage range as 3620mV and the maximum voltage as 3625mV. Similarly, the controller 50 can determine the minimum voltage of the second voltage range as 3625mV and the maximum voltage as 3630mV. Furthermore, the controller 50 can determine the minimum voltage of the third voltage range as 3630mV and the maximum voltage as 3635mV.

[0090] Figure 7 This is a schematic diagram illustrating an example of the operation of a controller installed in a device for diagnosing the state of a battery according to an embodiment of this application, which detects the time-varying values ​​of the voltage of each cell.

[0091] exist Figure 7 In the figure, the horizontal axis represents time (s), the vertical axis represents voltage (mV), the figure label 700 represents the voltage change curve of unit 1 within the current range C1, the figure label 710 represents the minimum voltage within the current range C1, and the figure label 720 represents the maximum voltage within the current range C1.

[0092] like Figure 7 As shown, controller 50 can detect the time it takes for the voltage of unit 1 to rise from a minimum voltage to a maximum voltage (e.g., 54 seconds). The time detected for all units in the current range C1 is recorded in this manner. Figure 8A As shown.

[0093] Figure 8A This is a schematic diagram showing the time required for the voltage of each cell within the current range C1 to rise from the minimum voltage to the maximum voltage, where the horizontal axis represents the cell number and the vertical axis represents time.

[0094] also, Figure 8B This is a schematic diagram showing the time required for the voltage of each cell within the current range C2 to rise from the minimum voltage to the maximum voltage. Figure 8C This is a schematic diagram showing the time required for the voltage of each cell within the current range C3 to rise from the minimum voltage to the maximum voltage. Figure 8D This is a schematic diagram showing the time required for the voltage of each cell within the current range C4 to rise from the minimum voltage to the maximum voltage. Figure 8E This is a schematic diagram showing the time required for the voltage of each cell within the current range C5 to rise from the minimum voltage to the maximum voltage. Figure 8F This is a schematic diagram showing the time required for the voltage of each cell within the current range C6 to rise from the minimum voltage to the maximum voltage.

[0095] Furthermore, when the voltage range of the current interval C1 is divided into 5mV voltage intervals, the controller 50 can generate 19 different frequency distributions within the current interval C1. This is a case of subdividing the voltage range, which can be used for more accurate diagnosis.

[0096] Figure 9 This is a schematic diagram showing the graded units of a controller installed in a device for diagnosing the state of a battery according to an embodiment of this application.

[0097] Controller 50 can determine such as Figure 8A The standard deviation (σ) of the time corresponding to each unit within the current range C1 shown determines the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0098] Controller 50 can determine such as Figure 8B The standard deviation (σ) of the time corresponding to each unit within the current range C2 shown is used to determine the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0099] Controller 50 can determine such as Figure 8C The standard deviation (σ) of the time corresponding to each unit within the current range C3 shown is used to determine the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0100] Controller 50 can determine such as Figure 8D The standard deviation (σ) of the time corresponding to each unit within the current range C4 shown is used to determine the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0101] Controller 50 can determine such as Figure 8E The standard deviation (σ) of the time corresponding to each unit within the current range C5 shown determines the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0102] Controller 50 can determine such as Figure 8F The standard deviation (σ) of the time corresponding to each unit within the current range C6 shown is used to determine the units included in the first threshold range (-3σ to -2σ and 2σ to 3σ) as warning level, and the units included in the second threshold range (less than -3σ and greater than 3σ) as danger level.

[0103] Therefore, controller 50 can generate, for example Figure 9 The table shown describes the units divided by level.

[0104] The controller 50 can diagnose the state of the battery 200 based on the number of cells contained within a threshold range (e.g., below -2σ and above 2σ). For example, when the number of cells contained within the threshold range exceeds a reference number (e.g., more than 5), the controller 50 can diagnose the state of the battery 200 as abnormal.

[0105] Furthermore, when the number of cells contained in the second threshold range (less than -3σ and greater than 3σ) exceeds the reference number, the controller 50 can diagnose the state of the battery 200 as abnormal.

[0106] Furthermore, when cells within the second threshold range (less than -3σ and greater than 3σ) are repeatedly detected in multiple current ranges, the controller 50 can diagnose the state of the battery 200 as abnormal.

[0107] Furthermore, when a cell classified as hazardous (e.g., cell number 121) is detected in all current ranges (C1 to C6), the controller 50 can provide a message indicating that the battery 200 should be replaced via the display 40.

[0108] Figure 10 This is a flowchart illustrating a method for diagnosing the state of a battery according to one embodiment of this application.

[0109] First, at 1001, the controller 50 monitors the charging current of the battery 200 and detects the current range that maintains a preset current change value.

[0110] Then, at 1002, controller 50 determines the minimum (or first) voltage and the maximum (or second) voltage of the voltage range that constitutes the current range.

[0111] Then, at 1003, the controller 50 detects the time required for the voltage of each cell of the battery 200 to rise from the minimum voltage to the maximum voltage within the current range.

[0112] Then, at 1004, the controller 50 diagnoses the state of the battery 200 based on the time corresponding to each cell.

[0113] Figure 11 This is a block diagram illustrating a computational system for performing a method for diagnosing the state of a battery according to each embodiment of this application.

[0114] Reference Figure 11 As described above, the method for diagnosing the state of a battery according to the embodiments of this application can be implemented by a computing system 1000. The computing system 1000 may include at least one processor 1100, a memory 1300, a user interface input device 1400, a user interface output device 1500, a storage device 1600, and a network interface 1700 connected via a system bus 1200.

[0115] Processor 1100 may be a central processing unit (CPU) or a semiconductor device that processes instructions stored in memory 1300 and / or storage device 1600. Memory 1300 and storage device 1600 may include various volatile or non-volatile storage media. For example, memory 1300 may include read-only memory (ROM) 1310 and random access memory (RAM) 1320.

[0116] Therefore, the processes of the methods or algorithms described in relation to the embodiments of this application can be directly implemented by hardware, software modules, or a combination thereof executed by processor 1100. The software modules can reside in storage media (i.e., memory 1300 and / or storage device 1600), such as RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, removable disk, or CD-ROM. In one example, the storage media is coupled to processor 1100, and processor 1100 can read information from and write information to the storage media. In another approach, the storage media can be integrated with processor 1100. Processor 1100 and storage media can reside in an application-specific integrated circuit (ASIC). The ASIC can reside in a user terminal. In yet another approach, processor 1100 and storage media can reside as separate components in the user terminal.

[0117] According to the embodiments of this application, by monitoring the charging current of the battery to detect the current range that maintains a preset current change value, the minimum voltage and maximum voltage within the current range are determined, the time required for the voltage of each cell of the battery to reach the maximum voltage from the minimum voltage within the current range is detected, and the state of the battery is diagnosed based on the time corresponding to each cell. This not only accurately diagnoses the state of the battery, but also accurately diagnoses the state of each cell that constitutes the battery.

[0118] The technologies, apparatuses, methods, and / or systems implementing such technologies described above may further include battery management based at least in part on the technologies described above. For example, the apparatuses and / or methods according to embodiments of this application may manage the battery based at least in part on diagnostic results of the battery's state diagnosed using the apparatuses and / or methods described above. For example, such battery management may control the battery cells and / or perform cell balancing to maintain balance among the battery cells based on diagnostic results of the battery's state obtained using the apparatuses and / or methods described above.

[0119] The foregoing description is a simplified example of the technical spirit of this application, and those skilled in the art can make various modifications and alterations to this application without departing from its essential characteristics. Therefore, the disclosed embodiments of this application do not limit the technical spirit of this application, but are illustrative, and the scope of the technical spirit of this application is not limited by the embodiments thereof. The scope of this application should be interpreted by the claims, and it should be understood that all technical spirit within the equivalent scope falls within the scope of this application.

Claims

1. An apparatus for diagnosing the state of a battery, the apparatus comprising: A current sensor configured to determine the charging current of the battery; A voltage sensor configured to determine the battery voltage; as well as The controller is configured as follows: Monitor the battery charging current to determine the diagnostic time interval for maintaining a preset current variation value. Determine a first voltage and a second voltage as the voltage range for the diagnostic time interval. Determine the time required for the voltage of each cell in a plurality of cells of the battery to rise from a first voltage to a second voltage within the diagnostic time interval. The battery status is diagnosed based on the time corresponding to each cell.

2. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured as follows: Determine the maximum and minimum voltage of each unit within the diagnostic time interval. The highest value among the minimum voltages of the plurality of units is determined as the first voltage of the diagnostic time interval. The lowest value among the maximum voltages of the plurality of units is determined as the second voltage of the diagnostic time interval.

3. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured as follows: Determine the standard deviation of the time corresponding to the plurality of units. The battery status is diagnosed based on the standard deviation.

4. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured as follows: Determine multiple diagnostic time intervals. Determine the first and second voltages within each diagnostic time interval. Determine the time required for each unit voltage to rise from a first voltage to a second voltage within each diagnostic time interval. The battery status is diagnosed based on the time corresponding to each cell within each of the plurality of diagnostic time intervals.

5. The apparatus for diagnosing the state of a battery according to claim 4, wherein, The controller is further configured as follows: Determine the standard deviation of the time corresponding to the plurality of units within each diagnostic time interval. The battery status is diagnosed based on the standard deviation of each diagnostic time interval.

6. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured as follows: The voltage range is divided into multiple voltage intervals. Determine the time required for each unit voltage within each voltage range to reach its maximum voltage from its minimum voltage. The battery status is diagnosed based on the voltage interval time corresponding to each cell within each voltage interval.

7. The apparatus for diagnosing the state of a battery according to claim 6, wherein, The controller is further configured as follows: Determine the standard deviation of the voltage interval time corresponding to the plurality of units within each voltage interval. The battery condition is diagnosed based on the standard deviation of each voltage range.

8. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured to monitor the battery charging current during all time intervals except the time interval between the state transition between closed-circuit voltage and open-circuit voltage.

9. The apparatus for diagnosing the state of a battery according to claim 1, wherein, The controller is further configured to determine the diagnostic time interval as the time interval between constant currents with a current change value of 0.

10. A method for diagnosing the state of a battery, the method comprising: The controller determines the diagnostic time interval for maintaining a preset current change value by monitoring the battery's charging current. The controller determines a first voltage and a second voltage as the voltage range for the diagnostic time interval; The controller determines the time required for the voltage of each cell in a plurality of cells of the battery to rise from a first voltage to a second voltage within the diagnostic time interval. The controller diagnoses the battery status based on the time corresponding to each cell.

11. The method according to claim 10, wherein, Determining the first voltage and the second voltage includes: Determine the maximum and minimum voltage of each unit within the diagnostic time interval; The highest value among the minimum voltages of the plurality of units is determined as the first voltage of the diagnostic time interval; The lowest value among the maximum voltages of the plurality of units is determined as the second voltage of the diagnostic time interval.

12. The method according to claim 10, wherein, Diagnostic battery status includes: Determine the standard deviation of the time corresponding to the plurality of units; The battery status is diagnosed based on the standard deviation.

13. The method according to claim 10, wherein, Diagnosing the battery status includes: determining a plurality of diagnostic time intervals, and diagnosing the battery status based on the time corresponding to each cell within each of the plurality of diagnostic time intervals.

14. The method according to claim 13, wherein, Diagnostic battery status includes: Determine the standard deviation of the time corresponding to each unit within each diagnostic time interval; The battery status is diagnosed based on the standard deviation of each diagnostic time interval.

15. The method according to claim 10, wherein, Diagnostic battery status includes: The battery status is diagnosed by dividing the voltage range into multiple voltage intervals and using the voltage interval time corresponding to each cell within each voltage interval.

16. The method according to claim 15, wherein, Diagnostic battery status includes: Determine the standard deviation of the time corresponding to the plurality of units within each voltage range; The battery condition is diagnosed based on the standard deviation of each voltage range.

17. The method according to claim 10, wherein, Determining the diagnostic time intervals includes monitoring the battery charging current during all time intervals except for the time interval between the state transition between closed-circuit voltage and open-circuit voltage.

18. The method according to claim 10, wherein, Determining the diagnostic time interval includes: defining the time interval of a constant current with a current change value of 0 as the diagnostic time interval.

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