Battery diagnosis device and operating method thereof

Abstract

A battery diagnosis device according to an embodiment disclosed in the present document may comprise: an acquisition unit for acquiring open circuit voltage (OCV) data of a plurality of battery cells; a calculation unit for calculating an OCV difference value between a first OCV value and a second OCV value for each of the plurality of battery cells on the basis of the OCV data, wherein the first OCV value corresponds to a first charge / discharge cycle, and the second OCV value corresponds to a second charge / discharge cycle after the first charge / discharge cycle; a normalization unit for normalizing OCV difference values of the plurality of battery cells to acquire normalized OCV difference values; an identification unit for identifying an abnormality-suspected battery cell among the plurality of battery cells on the basis of the normalized OCV difference values; and a diagnosis unit for diagnosing an abnormality of the abnormality-suspected battery cell on the basis of an OCV deviation value between a second OCV value of the identified abnormality-suspected battery cell and a representative value of the second OCV values of the plurality of battery cells.

Description

Battery diagnostic device and its operating method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Republic of Korea Patent Application No. 10-2024-0002060, filed January 5, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to a battery diagnostic device and an operating method thereof.

[0005] Research and development on secondary batteries has been actively conducted recently. The term "secondary battery" refers to a rechargeable battery, encompassing both conventional Ni / Cd and Ni / MH batteries, as well as more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries boast a significantly higher energy density than conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form, making them ideal power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, drawing attention as a next-generation energy storage medium.

[0006] Additionally, secondary batteries can be utilized as battery packs, which typically include battery modules in which multiple battery cells are connected in series and / or parallel. Furthermore, secondary batteries can be utilized as battery racks, which include multiple battery modules and a rack frame that accommodates these battery modules.

[0007] Battery cells, battery modules, battery packs, or battery racks like these can be utilized in a variety of devices. For example, batteries can be used in mobile devices such as cell phones, laptops, smartphones, and tablets, as well as in electric vehicles (EVs, HEVs, PHEVs) and large-capacity energy storage systems (ESS).

[0008] These batteries can have their status and operation managed and controlled by a battery management system (BMS). The BMS can be included with the batteries in a single device.

[0009] Additionally, the battery management system can manage and control the battery while being separated from the device containing the battery. For example, the battery management system can be implemented as a separate server device. In this case, the battery management system can collect battery data and vehicle data from vehicles and other devices, and utilize the collected data to manage and control the battery.

[0010] Meanwhile, if a battery is defective, the risk of damage to devices containing the battery (e.g., EVs, ESS) may increase. Therefore, a method is needed to detect abnormal battery conditions and reduce the risk of damage to devices containing the battery.

[0011] The embodiments disclosed in this document can provide a battery diagnostic device and an operating method thereof that can diagnose a battery abnormality using a charge / discharge cycle OCV difference value.

[0012] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the descriptions below.

[0013] According to an embodiment disclosed in the present document, a battery diagnosis device may include an acquisition unit that acquires OCV (Open Circuit Voltage) data of a plurality of battery cells, a calculation unit that calculates, for each of the plurality of battery cells, an OCV difference value between a first OCV value corresponding to a first charge / discharge cycle and a second OCV value corresponding to a second charge / discharge cycle after the first charge / discharge cycle, based on the OCV data, a normalization unit that normalizes the OCV difference values ​​of the plurality of battery cells to obtain normalized OCV difference values, an identification unit that identifies a suspected abnormal battery cell among the plurality of battery cells based on the normalized OCV difference values, and a diagnosis unit that diagnoses an abnormality of the suspected abnormal battery cell based on an OCV deviation value between the second OCV value of the identified suspected abnormal battery cell and a representative value of the second OCV values ​​of the plurality of battery cells.

[0014] In a battery diagnosis device according to an embodiment disclosed in this document, the normalization unit can normalize the OCV difference values ​​of the plurality of battery cells based on the following mathematical expression 1 to obtain the normalized OCV difference values.

[0015] [Mathematical Formula 1]

[0016]

[0017] (In Equation 1, dOCV i is the OCV difference value of the i-th battery cell among the plurality of battery cells, dOCV min is the minimum value of the OCV difference values ​​of the plurality of battery cells, dOCV max is the maximum value of the OCV difference values ​​of the plurality of battery cells.)

[0018] In a battery diagnostic device according to an embodiment disclosed in this document, the identification unit can identify the suspected abnormal battery cell among the plurality of battery cells based on a deviation between the normalized OCV difference values.

[0019] In a battery diagnostic device according to an embodiment disclosed in this document, if a deviation between a maximum value and a second largest value among the normalized OCV difference values ​​is greater than or equal to a first threshold value, the identification unit can identify a battery cell having the maximum value as the suspected abnormal battery cell.

[0020] In a battery diagnostic device according to an embodiment disclosed in this document, if a deviation between a minimum value and a second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value, the identification unit can identify a battery cell having the minimum value as the suspected abnormal battery cell.

[0021] In a battery diagnostic device according to an embodiment disclosed in this document, the diagnostic unit can diagnose the suspected abnormal battery cell as an abnormal battery cell if the OCV deviation value of the suspected abnormal battery cell is equal to or greater than a third threshold value.

[0022] In a battery diagnostic device according to an embodiment disclosed in this document, the first OCV value may be an OCV value corresponding to a charging cycle included in the first charge / discharge cycle, and the second OCV value may be an OCV value corresponding to a charging cycle included in the second charge / discharge cycle.

[0023] In a battery diagnostic device according to an embodiment disclosed in this document, the first OCV value may be an OCV value corresponding to a discharge cycle included in the first charge / discharge cycle, and the second OCV value may be an OCV value corresponding to a discharge cycle included in the second charge / discharge cycle.

[0024] An operating method of a battery diagnosis device according to an embodiment disclosed in the present document may include an operation of acquiring OCV (Open Circuit Voltage) data of a plurality of battery cells, an operation of calculating, for each of the plurality of battery cells, an OCV difference value between a first OCV value corresponding to a first charge / discharge cycle and a second OCV value corresponding to a second charge / discharge cycle after the first charge / discharge cycle, based on the OCV data, an operation of normalizing the OCV difference values ​​of the plurality of battery cells to acquire normalized OCV difference values, an operation of identifying a suspected abnormal battery cell among the plurality of battery cells based on the normalized OCV difference values, and an operation of diagnosing an abnormality of the suspected abnormal battery cell based on an OCV deviation value between the second OCV value of the identified suspected abnormal battery cell and a representative value of the second OCV values ​​of the plurality of battery cells.

[0025] In the operating method of the battery diagnosis device according to one embodiment disclosed in this document, the operation of obtaining the normalized OCV difference values ​​may include an operation of obtaining the normalized OCV difference values ​​by normalizing the OCV difference values ​​of the plurality of battery cells based on the mathematical expression 1.

[0026] In the operating method of the battery diagnosis device according to one embodiment disclosed in this document, the operation of identifying the suspected abnormal battery cell may include an operation of identifying the suspected abnormal battery cell among the plurality of battery cells based on a deviation between the normalized OCV difference values.

[0027] In the operating method of the battery diagnosis device according to one embodiment disclosed in the present document, the operation of identifying the suspected abnormal battery cell may include an operation of identifying the battery cell having the maximum value as the suspected abnormal battery cell if the deviation between the maximum value and the second largest value among the normalized OCV difference values ​​is greater than or equal to a first threshold value.

[0028] In the operating method of the battery diagnosis device according to one embodiment disclosed in the present document, the operation of identifying the suspected abnormal battery cell may include an operation of identifying the battery cell having the minimum value as the suspected abnormal battery cell if the deviation between the minimum value and the second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value.

[0029] In the operating method of the battery diagnosis device according to one embodiment disclosed in this document, the operation of diagnosing an abnormality in the suspected abnormal battery cell may include an operation of diagnosing the suspected abnormal battery cell as an abnormal battery cell if the OCV deviation value of the suspected abnormal battery cell is equal to or greater than a third threshold value.

[0030] In the operating method of the battery diagnosis device according to one embodiment disclosed in this document, the first OCV value may be an OCV value corresponding to a charging cycle included in the first charge / discharge cycle, and the second OCV value may be an OCV value corresponding to a charging cycle included in the second charge / discharge cycle.

[0031] According to the embodiments disclosed in this document, micro-abnormal behavior of battery voltage can be accurately diagnosed through normalization of OCV difference values.

[0032] In addition, various effects may be provided, either directly or indirectly, through this document.

[0033] FIG. 1 is a block diagram of a battery diagnostic device according to one embodiment.

[0034] FIGS. 2A and 2B are graphs showing OCV difference values ​​calculated for each of a plurality of battery cells by a battery diagnostic device according to one embodiment.

[0035] FIG. 3 is a graph showing normalized OCV difference values ​​obtained by normalizing OCV difference values ​​by a battery diagnostic device according to one embodiment.

[0036] Figure 4 is a flowchart illustrating the operation of a battery diagnostic device according to one embodiment.

[0037] Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0038] The various embodiments and terminology used in this document are not intended to limit the technical features described in this document to specific embodiments, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiments. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise.

[0039] In this document, the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", "first", "second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the corresponding element from other corresponding elements, and do not limit the corresponding elements in any other respect (e.g., importance or order) unless specifically stated otherwise.

[0040] In this document, whenever a component (e.g., a first component) is referred to as being “connected,” “coupled,” or “connected,” with or without the terms “functionally” or “communicatively,” or “coupled” or “connected,” it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or via a third component.

[0041] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0042] FIG. 1 is a block diagram of a battery diagnostic device according to one embodiment.

[0043] The battery diagnostic device (101) described below can be implemented as a BMS (Battery Management System) in an electronic device (102), but can also be implemented as various external devices such as a server, cloud, charger, or charger / discharger.

[0044] Referring to FIG. 1, a battery diagnostic device (101) can be connected to an electronic device (102) and a user terminal (104) via wires and / or wirelessly.

[0045] According to one embodiment, the connection (103) between the battery diagnostic device (101) and the electronic device (102) may be a communication connection via a wired and / or wireless network. In one embodiment, the wired network may be based on a local area network (LAN) communication or a power line communication. In one embodiment, the wireless network may be based on a short-range communication network (e.g., Bluetooth, wireless fidelity (WiFi), or infrared data association (IrDA)) or a wide-range communication network (cellular network, 4G network, 5G network).

[0046] According to another embodiment, the connection (103) between the battery diagnostic device (101) and the electronic device (102) may be a connection via a device-to-device communication method (e.g., a bus, a general purpose input and output (GPIO), a serial peripheral interface (SPI), or a mobile industry processor interface (MIPI)).

[0047] According to one embodiment, the electronic device (102) may be a mobile device (e.g., a mobile phone, a laptop computer, a smart phone, a smart pad), an electric vehicle (e.g., an electric vehicle (EV), a hybrid EV (HEV), a plug-in HEV (PHEV), a fuel cell EV (FCEV)), an energy storage system (ESS), or a battery swapping system (BSS).

[0048] According to one embodiment, the electronic device (102) may include a plurality of battery cells (151, 153, 155). According to one embodiment, the plurality of battery cells (151, 153, 155) may be included in one battery module or one battery pack.

[0049] According to one embodiment, the connection (105) between the battery diagnostic device (101) and the user terminal (104) may be a communication connection via a wired and / or wireless network.

[0050] According to one embodiment, the user terminal (104) may be a mobile device (e.g., a mobile phone, a laptop computer, a smart phone, a smart pad), or a personal computer (PC). According to one embodiment, the battery diagnostic device (101) may provide information related to the diagnostic results of the battery unit (151, 153, or 155) to the user terminal (104).

[0051] According to one embodiment, the battery diagnostic device (101) may include a communication circuit (110), a sensor (120), a memory (130), and a processor (140). Depending on the embodiment, the battery diagnostic device (101) illustrated in FIG. 1 may further include at least one component (e.g., a display, an input device, or an output device) other than the components illustrated in FIG. 1, or may omit at least one component (e.g., a sensor (120)) among the components illustrated in FIG. 1. For example, when the battery diagnostic device (101) is implemented as an external electronic device separate from the electronic device (102), such as a server or a cloud, the battery diagnostic device (101) may obtain status information of a plurality of battery cells (151, 153, 155) using the communication circuit (110). In this case, the battery diagnostic device (101) may not include the sensor (120).

[0052] According to one embodiment, the communication circuit (110) can establish a wired communication channel and / or a wireless communication channel between the battery diagnostic device (101) and the electronic device (102) and / or the user terminal (104), and transmit and receive data with the electronic device (102) and / or the user terminal (104) through the established communication channel.

[0053] According to one embodiment, the sensor (120) can measure information (e.g., voltage, current, temperature, etc.) related to the status of a plurality of battery cells (151, 153, 155) of the electronic device (102). For example, when the battery diagnosis device (101) is implemented as a BMS within the electronic device, the battery diagnosis device (101) can directly measure the status values ​​of the plurality of battery cells (151, 153, 155) using the sensor (120).

[0054] According to one embodiment, the communication circuit (110) and / or the sensor (120) may obtain time series data related to the states of the plurality of battery cells (151, 153, 155). In one embodiment, the time series data related to the states of the plurality of battery cells (151, 153, 155) may be data representing voltage, current, resistance, state of charge (SOC), state of health (SOH), and / or temperature of the plurality of battery cells (151, 153, 155) over time.

[0055] According to one embodiment, the memory (130) may include volatile memory and / or non-volatile memory.

[0056] According to one embodiment, the memory (130) may store data used by at least one component (e.g., processor (140)) of the battery diagnosis device (101). For example, the data may include software (or instructions related thereto), input data, or output data. In one embodiment, the instructions, when executed by the processor (140), may cause the battery abnormality diagnosis device (101) to perform operations defined by the instructions.

[0057] According to one embodiment, the memory (130) may include one or more software (e.g., an acquisition unit (131), a production unit (132), a normalization unit (133), an identification unit (134), and a diagnosis unit (135)).

[0058] According to one embodiment, the processor (140) may include a central processing unit, an application processor, a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor.

[0059] According to one embodiment, the processor (140) may execute software (e.g., acquisition unit (131), calculation unit (132), normalization unit (133), identification unit (134), and diagnosis unit (135)) stored in the memory (130) to control at least one other component (e.g., hardware or software component) of the battery diagnostic device (101) connected to the processor (140) and perform various data processing or operations.

[0060] Hereinafter, with reference to FIGS. 2A, 2B, and 3, a method for diagnosing an abnormality of a plurality of battery cells (151, 153, 155) through an acquisition unit (131), a calculation unit (132), a normalization unit (133), an identification unit (134), and a diagnosis unit (135) by a battery diagnosis device (101) will be described.

[0061] FIG. 2A and FIG. 2B are graphs showing OCV difference values ​​calculated for each of a plurality of battery cells by a battery diagnostic device according to an embodiment. FIG. 3 is a graph showing normalized OCV difference values ​​obtained by normalizing OCV difference values ​​by a battery diagnostic device according to an embodiment.

[0062] According to one embodiment, the acquisition unit (131) can acquire OCV (Open Circuit Voltage) data of a plurality of battery cells (151, 153, 155). For example, the acquisition unit (131) can measure voltage, current, and / or temperature of the plurality of battery cells (151, 153, 155) and generate OCV data based on the measured information. In this case, the acquisition unit (131) can use the sensor (120) to measure voltage, current, and / or temperature of the plurality of battery cells (151, 153, 155). As another example, the acquisition unit (131) can receive the OCV data of the plurality of battery cells (151, 153, 155) generated by the electronic device (102) from the electronic device (102) using the communication circuit (110).

[0063] According to one embodiment, the calculation unit (132) may calculate an OCV difference value for each of a plurality of battery cells (151, 153, 155) based on the OCV data. The OCV difference value may be a difference value between two OCV values ​​corresponding to two charge / discharge cycles among a plurality of charge / discharge cycles included in a time period of the OCV data. Here, the charge / discharge cycle may include a charge cycle and a discharge cycle.

[0064] According to one embodiment, the OCV difference value may be a difference value between a first OCV value corresponding to a first charge / discharge cycle among the plurality of charge / discharge cycles and a second OCV value corresponding to a second charge / discharge cycle among the plurality of charge / discharge cycles. In this case, the second charge / discharge cycle may be a cycle adjacent to the first charge / discharge cycle and subsequent to the first charge / discharge cycle. In addition, the OCV difference value may be a value obtained by subtracting the first OCV value from the second OCV value.

[0065] Hereinafter, the current charge / discharge cycle to be diagnosed may be referred to as the second charge / discharge cycle, and the immediately preceding charge / discharge cycle may be referred to as the first charge / discharge cycle. In addition, the OCV value of the battery cell (151, 153, and / or 155) corresponding to the first charge / discharge cycle may be referred to as the first OCV value, and the OCV value of the battery cell (151, 153, and / or 155) corresponding to the second charge / discharge cycle may be referred to as the second OCV value.

[0066] According to one embodiment, the output unit (132) can output the OCV difference value based on one type of charge cycle or discharge cycle included in the charge / discharge cycle.

[0067] For example, the calculation unit (132) may calculate an OCV difference value between a first OCV value corresponding to a first charging cycle among a plurality of charging cycles included in a time section of the OCV data and a second OCV value corresponding to a second charging cycle after the first charging cycle. In this case, the OCV value corresponding to each charging cycle may be selected as an OCV value at a time point after a specified time (e.g., 2 hours) has passed after each charging cycle ends. For example, the calculation unit (132) may calculate a difference value between a first OCV value at a time point after a specified time has passed after the end of the first charging cycle and a second OCV value at a time point after a specified time has passed after the end of the second charging cycle as the OCV difference value.

[0068] As another example, the calculation unit (132) can calculate an OCV difference value between a first OCV value corresponding to a first discharge cycle among a plurality of discharge cycles included in a time section of the OCV data and a second OCV value corresponding to a second discharge cycle after the first discharge cycle. In this case, the OCV value corresponding to each discharge cycle can be selected as an OCV value at a time point after a specified time (e.g., 2 hours) has passed after each discharge cycle ends. For example, the calculation unit (132) can calculate a difference value between a first OCV value at a time point after a specified time has passed after the end of the first discharge cycle and a second OCV value at a time point after a specified time has passed after the end of the second discharge cycle as the OCV difference value.

[0069] Referring to FIGS. 2a and 2b, graphs (210, 220) showing OCV difference values ​​for charge cycles or discharge cycles of battery cells to be diagnosed, produced by the production unit (132), can be confirmed.

[0070] In each graph (210, 220), the OCV difference values ​​corresponding to a specific charge cycle or a specific discharge cycle correspond to each of the battery cells to be diagnosed, and may be the difference value between the OCV value corresponding to the specific cycle and the OCV value corresponding to the previous cycle. For example, in the graph (210), the OCV difference value corresponding to the third charge cycle of the first battery cell among the battery cells to be diagnosed may be the difference value between the OCV value corresponding to the third charge cycle of the first battery cell and the OCV value corresponding to the second charge cycle.

[0071] According to one embodiment, the normalization unit (133) can normalize the OCV difference values ​​of the plurality of battery cells (151, 153, 155) calculated by the calculation unit (132) to obtain normalized OCV difference values. For example, the normalization unit (133) can normalize the OCV difference values ​​based on the following mathematical expression 1 to obtain the normalized OCV difference values.

[0072]

[0073] In the above mathematical expression 1, dOCV i is the OCV difference value of the i-th battery cell (where i is a natural number) among multiple battery cells (151, 153, 155), dOCV min is the minimum value of the OCV difference values ​​of multiple battery cells (151, 153, 155), dOCV max is the maximum value of the OCV difference values ​​of multiple battery cells (151, 153, 155).

[0074] Referring to FIG. 3, a graph (300) representing normalized OCV difference values ​​for the charge cycles of battery cells to be diagnosed obtained by the normalization unit (133) can be confirmed. Specifically, the graph (300) can represent normalized OCV difference values ​​obtained by the normalization unit (133) by normalizing the OCV difference values ​​of battery cells to be diagnosed according to the graph (210) of FIG. 2A.

[0075] In the graph (300), the normalized OCV difference values ​​corresponding to a specific charging cycle correspond to each of the battery cells to be diagnosed, and may be values ​​calculated by inputting the OCV difference values ​​of the battery cells to be diagnosed corresponding to a specific charging cycle into the above mathematical expression 1. For example, in the graph (300), the normalized OCV difference value corresponding to the 13th charging cycle of the first battery cell among the battery cells to be diagnosed may be a value calculated by inputting the minimum value and the maximum value of the OCV difference value corresponding to the 13th charging cycle of the first battery cell and the OCV difference values ​​corresponding to the 13th charging cycle of the battery cells to be diagnosed into the above mathematical expression 1.

[0076] According to one embodiment, the identification unit (134) can identify a suspected abnormal battery cell among the plurality of battery cells (151, 153, 155) based on the normalized OCV difference values ​​of the plurality of battery cells (151, 153, 155) obtained by the normalization unit (133).

[0077] According to one embodiment, the identification unit (134) can identify a suspected abnormal battery cell among a plurality of battery cells (151, 153, 155) based on a deviation between the normalized OCV difference values. In this case, the deviation may be a value obtained by subtracting a smaller value from a larger value among two normalized OCV difference values.

[0078] For example, if the deviation between the maximum value and the second largest value among the normalized OCV difference values ​​is greater than or equal to a first threshold value (e.g., 0.67), the identification unit (134) can identify the battery cell having the maximum value as a suspected abnormal battery cell. According to the graph (300), if the deviation (305) between the maximum value (301) and the second largest value (303) among the normalized OCV difference values ​​in the 13th charging cycle is greater than or equal to the first threshold value, the identification unit (134) can identify the 6th battery cell having the maximum value (301) as a suspected abnormal battery cell.

[0079] As another example, if the deviation between the minimum value and the second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value (e.g., 0.8), the identification unit (134) may identify the battery cell having the minimum value as a suspected abnormal battery cell. According to the graph (300), if the deviation (315) between the minimum value (311) and the second smallest value (313) among the normalized OCV difference values ​​in the 14th charging cycle is greater than or equal to the second threshold value, the identification unit (134) may identify the 6th battery cell having the minimum value (311) as a suspected abnormal battery cell.

[0080] According to one embodiment, the diagnostic unit (135) can diagnose an abnormality in the suspected abnormal battery cell based on an OCV deviation value between a second OCV value corresponding to the second charge / discharge cycle of the suspected abnormal battery cell identified by the identification unit (134) and a representative value of second OCV values ​​corresponding to the second charge / discharge cycles of a plurality of battery cells (151, 153, 155). Here, the representative value can be selected as an average value of the second OCV values ​​or a central value of the second OCV values.

[0081] For example, the diagnostic unit (135) can calculate an OCV deviation value between the second OCV value of the sixth battery cell identified as a suspected abnormal battery cell according to the graph (300) and the representative value of the second OCV values ​​of the first to eighth battery cells through the graph (210), and diagnose an abnormality in the sixth battery cell based on the calculated OCV deviation value.

[0082] According to one embodiment, the diagnostic unit (135) can diagnose the suspected abnormal battery cell as an abnormal battery cell if the OCV deviation value of the suspected abnormal battery cell is greater than or equal to the third threshold value.

[0083] According to one embodiment, the battery diagnostic device (101) can repeatedly perform the operations of the above-described calculation unit (132), normalization unit (133), identification unit (134), and diagnostic unit (135) on the remaining battery cells for each unit time (e.g., charge / discharge cycle) except for the abnormal battery cells diagnosed by the diagnostic unit (135) until no abnormal battery cells are diagnosed.

[0084] Fig. 4 is a flowchart illustrating the operation of a battery diagnostic device according to one embodiment. Fig. 4 can be explained using the configurations of Fig. 1.

[0085] The embodiment illustrated in FIG. 4 is only one embodiment, and the order of steps according to various embodiments of the present invention may be different from that illustrated in FIG. 4, and some of the steps illustrated in FIG. 4 may be omitted, the order between steps may be changed, or steps may be merged.

[0086] Referring to FIG. 4, in operation 405, the battery diagnostic device (101) may obtain OCV data of a plurality of battery cells (151, 153, 155). For example, the battery diagnostic device (101) may measure voltage, current, and / or temperature of the plurality of battery cells (151, 153, 155) and generate OCV data based on the measured information. In this case, the battery diagnostic device (101) may use a sensor (120) to measure voltage, current, and / or temperature of the plurality of battery cells (151, 153, 155). As another example, the battery diagnostic device (101) may receive OCV data of the plurality of battery cells (151, 153, 155) generated by the electronic device (102) from the electronic device (102) using a communication circuit (110).

[0087] In operation 410, the battery diagnostic device (101) may calculate an OCV difference value for each of the plurality of battery cells (151, 153, 155) based on the OCV data acquired in operation 405. The OCV difference value may be a difference value between two OCV values ​​corresponding to each of two charge / discharge cycles among the plurality of charge / discharge cycles included in the time period of the OCV data. Here, the charge / discharge cycle may include a charge cycle and a discharge cycle.

[0088] According to one embodiment, the OCV difference value may be a difference value between a first OCV value corresponding to a first charge / discharge cycle among the plurality of charge / discharge cycles and a second OCV value corresponding to a second charge / discharge cycle among the plurality of charge / discharge cycles. In this case, the second charge / discharge cycle may be a cycle adjacent to the first charge / discharge cycle and subsequent to the first charge / discharge cycle. In addition, the OCV difference value may be a value obtained by subtracting the first OCV value from the second OCV value.

[0089] According to one embodiment, the battery diagnostic device (101) can calculate the OCV difference value based on one type of charge cycle or discharge cycle included in the charge / discharge cycle.

[0090] For example, the battery diagnosis device (101) can calculate an OCV difference value between a first OCV value corresponding to a first charging cycle among a plurality of charging cycles included in a time section of OCV data and a second OCV value corresponding to a second charging cycle after the first charging cycle. In this case, the OCV value corresponding to each charging cycle can be selected as an OCV value at a time point after a specified time (e.g., 2 hours) has passed after each charging cycle ends. For example, the battery diagnosis device (101) can calculate a difference value between a first OCV value at a time point after a specified time has passed after the end of the first charging cycle and a second OCV value at a time point after a specified time has passed after the end of the second charging cycle as the OCV difference value.

[0091] As another example, the battery diagnosis device (101) can calculate an OCV difference value between a first OCV value corresponding to a first discharge cycle among a plurality of discharge cycles included in a time section of OCV data and a second OCV value corresponding to a second discharge cycle after the first discharge cycle. In this case, the OCV value corresponding to each discharge cycle can be selected as an OCV value at a time point after a specified time (e.g., 2 hours) has passed after each discharge cycle ends. For example, the battery diagnosis device (101) can calculate a difference value between a first OCV value at a time point after a specified time has passed after the end of the first discharge cycle and a second OCV value at a time point after a specified time has passed after the end of the second discharge cycle as the OCV difference value.

[0092] In operation 415, the battery diagnosis device (101) can normalize the OCV difference values ​​of the plurality of battery cells (151, 153, 155) calculated in operation 410 to obtain normalized OCV difference values. For example, the battery diagnosis device (101) can normalize the OCV difference values ​​based on the above mathematical expression 1 to obtain the normalized OCV difference values.

[0093] In operation 420, the battery diagnostic device (101) can identify a suspected abnormal battery cell among the plurality of battery cells (151, 153, 155) based on the normalized OCV difference values ​​of the plurality of battery cells (151, 153, 155) obtained in operation 415.

[0094] According to one embodiment, the battery diagnostic device (101) can identify a battery cell suspected of being abnormal among a plurality of battery cells (151, 153, 155) based on a deviation between the normalized OCV difference values. In this case, the deviation may be a value obtained by subtracting a smaller value from a larger value among two normalized OCV difference values.

[0095] For example, if the deviation between the maximum value and the second largest value among the normalized OCV difference values ​​is greater than or equal to a first threshold value (e.g., 0.67), the battery diagnostic device (101) can identify the battery cell having the maximum value as a suspected abnormal battery cell.

[0096] As another example, the battery diagnostic device (101) can identify a battery cell having the minimum value as a suspected abnormal battery cell if the deviation between the minimum value and the second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value (e.g., 0.8).

[0097] In operation 425, the battery diagnosis device (101) can diagnose an abnormality in the suspected abnormal battery cell identified in operation 420. According to one embodiment, the battery diagnosis device (101) can diagnose an abnormality in the suspected abnormal battery cell based on an OCV deviation value between a second OCV value corresponding to a second charge / discharge cycle of the suspected abnormal battery cell and a representative value of second OCV values ​​corresponding to the second charge / discharge cycles of the plurality of battery cells (151, 153, 155). Here, the representative value can be selected as an average value of the second OCV values ​​or a central value of the second OCV values.

[0098] According to one embodiment, the battery diagnostic device (101) can diagnose the suspected abnormal battery cell as an abnormal battery cell if the OCV deviation value of the suspected abnormal battery cell is equal to or greater than a third threshold value.

[0099] According to one embodiment, the battery diagnostic device (101) may repeat the above-described operations 410 to 425 for the remaining battery cells every unit time (e.g., charge / discharge cycle) except for the abnormal battery cell diagnosed in operation 425 until no abnormal battery cell is diagnosed.

[0100] The terms "include," "comprise," or "have" used herein, unless otherwise specifically stated, imply that the corresponding component may be included, and therefore should be interpreted to include other components rather than to exclude other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document pertain, unless otherwise defined. Commonly used terms, such as terms defined in dictionaries, should be interpreted to be consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense, unless explicitly defined in this document.

Claims

1. An acquisition unit that acquires OCV (Open Circuit Voltage) data of multiple battery cells; A calculation unit that calculates, for each of the plurality of battery cells, an OCV difference value between a first OCV value corresponding to a first charge / discharge cycle and a second OCV value corresponding to a second charge / discharge cycle after the first charge / discharge cycle based on the above OCV data; A normalization unit that normalizes the OCV difference values ​​of the plurality of battery cells to obtain normalized OCV difference values; An identification unit for identifying a suspected abnormal battery cell among the plurality of battery cells based on the normalized OCV difference values; and A battery diagnostic device, comprising a diagnostic unit that diagnoses an abnormality in the suspected abnormal battery cell based on an OCV deviation value between the second OCV value of the identified suspected abnormal battery cell and a representative value of the second OCV values ​​of the plurality of battery cells.

2. In claim 1, A battery diagnostic device, wherein the normalization unit normalizes the OCV difference values ​​of the plurality of battery cells based on the following mathematical expression 1 to obtain the normalized OCV difference values. [Mathematical formula 1] (In Equation 1, dOCV i is the OCV difference value of the i-th battery cell among the plurality of battery cells, dOCV min is the minimum value of the OCV difference values ​​of the above plurality of battery cells, dOCV max is the maximum value of the OCV difference values ​​of the above plurality of battery cells.) 3. In claim 1, A battery diagnostic device, wherein the identification unit identifies the suspected abnormal battery cell among the plurality of battery cells based on the deviation between the normalized OCV difference values.

4. In claim 3, The above identification unit is a battery diagnostic device, wherein, if a deviation between a maximum value and a second largest value among the normalized OCV difference values ​​is greater than a first threshold value, the battery cell having the maximum value is identified as the suspected abnormal battery cell.

5. In claim 3, The above identification unit is a battery diagnostic device, wherein, if a deviation between a minimum value and a second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value, the battery cell having the minimum value is identified as the suspected abnormal battery cell.

6. In claim 1, A battery diagnostic device, wherein the diagnostic unit diagnoses the suspected abnormal battery cell as an abnormal battery cell if the OCV deviation value of the suspected abnormal battery cell is equal to or greater than a third threshold value.

7. In claim 1, The above first OCV value is an OCV value corresponding to a charging cycle included in the first charge / discharge cycle, A battery diagnostic device, wherein the second OCV value is an OCV value corresponding to a charging cycle included in the second charge / discharge cycle.

8. In claim 1, The above first OCV value is an OCV value corresponding to a discharge cycle included in the first charge / discharge cycle, A battery diagnostic device, wherein the second OCV value is an OCV value corresponding to a discharge cycle included in the second charge / discharge cycle.

9. An operation to acquire OCV (Open Circuit Voltage) data of multiple battery cells; An operation of calculating, for each of the plurality of battery cells, an OCV difference value between a first OCV value corresponding to a first charge / discharge cycle and a second OCV value corresponding to a second charge / discharge cycle after the first charge / discharge cycle based on the above OCV data; An operation of normalizing the OCV difference values ​​of the plurality of battery cells to obtain normalized OCV difference values; An operation of identifying a suspected abnormal battery cell among the plurality of battery cells based on the normalized OCV difference values; and An operating method of a battery diagnosis device, comprising an operation of diagnosing an abnormality in a suspected abnormal battery cell based on an OCV deviation value between a second OCV value of the identified suspected abnormal battery cell and a representative value of second OCV values ​​of the plurality of battery cells.

10. In claim 9, A method for operating a battery diagnostic device, wherein the operation of obtaining the normalized OCV difference values ​​includes an operation of obtaining the normalized OCV difference values ​​by normalizing the OCV difference values ​​of the plurality of battery cells based on the following mathematical expression 1. [Mathematical formula 1] (In Equation 1, dOCV i is the OCV difference value of the i-th battery cell among the plurality of battery cells, dOCV min is the minimum value of the OCV difference values ​​of the above plurality of battery cells, dOCV max is the maximum value of the OCV difference values ​​of the above plurality of battery cells.) 11. In claim 9, A method for operating a battery diagnostic device, wherein the operation of identifying the suspected abnormal battery cell includes an operation of identifying the suspected abnormal battery cell among the plurality of battery cells based on a deviation between the normalized OCV difference values.

12. In claim 11, A method for operating a battery diagnostic device, wherein the operation of identifying the suspected abnormal battery cell includes an operation of identifying the battery cell having the maximum value as the suspected abnormal battery cell if a deviation between the maximum value and the second largest value among the normalized OCV difference values ​​is greater than or equal to a first threshold value.

13. In claim 11, An operation method of a battery diagnosis device, wherein the operation of identifying the suspected abnormal battery cell includes an operation of identifying a battery cell having the minimum value as the suspected abnormal battery cell if a deviation between a minimum value and a second smallest value among the normalized OCV difference values ​​is greater than or equal to a second threshold value.

14. In claim 9, An operation method of a battery diagnosis device, wherein the operation of diagnosing an abnormality of the above-mentioned abnormal suspected battery cell includes an operation of diagnosing the above-mentioned abnormal suspected battery cell as an abnormal battery cell if the OCV deviation value of the above-mentioned abnormal suspected battery cell is equal to or greater than a third threshold value.

15. In claim 9, The above first OCV value is an OCV value corresponding to a charging cycle included in the first charge / discharge cycle, A method of operating a battery diagnostic device, wherein the second OCV value is an OCV value corresponding to a charging cycle included in the second charge / discharge cycle.

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