Battery diagnostic device and method

Abstract

A battery diagnostic device according to one embodiment of the present invention includes a data acquiring unit configured to acquire a resistance value and a voltage value of a battery, a profile generating unit configured to generate a profile indicating a correspondence relationship between the resistance value and the voltage value of the battery acquired by the data acquiring unit, and a control unit configured to set a reference range in the profile received from the profile generating unit, and to diagnose an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2022-0079279 filed on June 28, 2022, and Korean Patent Application No. 10-2023-0082222 filed on June 26, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly to a battery diagnostic device and method capable of diagnosing the state of a battery in a non-destructive manner. [Background technology]

[0003] In recent years, as the demand for portable electronic products such as notebooks, video cameras, and mobile phones has grown rapidly and the development of electric vehicles, energy storage batteries, robots, and artificial satellites has progressed in earnest, research into high-performance batteries that can be repeatedly charged and discharged is being actively conducted.

[0004] Currently commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] Such batteries deteriorate as they are repeatedly charged and discharged. For example, gas generation inside the battery can reduce the electron transfer ability in the electrodes, causing imbalance in negative electrode deterioration.

[0006] The gases inside the battery can also cause the battery housing to bulge and vent the battery seal, which can release the gases inside the battery and lead to a battery fire.

[0007] That is, if the battery condition is not diagnosed quickly, unexpected problems such as reduced performance, fire and explosion may occur. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery diagnostic apparatus and method that can diagnose the state of a battery in a non-destructive manner through profile analysis.

[0009] Other objects and advantages of the present invention can be understood from the following description and will become more apparent from the embodiments of the present invention. Also, the objects and advantages of the present invention can be realized by the means and combinations thereof as set forth in the claims. [Means for solving the problem]

[0010] A battery diagnostic device according to one aspect of the present invention includes a data acquisition unit configured to acquire a resistance value and a voltage value of a battery, a profile generation unit configured to generate a profile indicating a correspondence relationship between the resistance value and the voltage value of the battery acquired by the data acquisition unit, and a control unit configured to set a reference range in the profile received from the profile generation unit, and to diagnose an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range.

[0011] The control unit may be configured to set a reference line indicating a rate of change of the resistance value with respect to the voltage value in the profile, and to set the reference range based on the reference line.

[0012] The control unit may be configured to set the reference range to within a predetermined critical value from the reference line.

[0013] The controller may be configured to set the baseline outside of target resistance and voltage values ​​most recently included in the profile.

[0014] The data acquisition unit may be configured to acquire the voltage value and the resistance value at a point in time when the battery has maintained a rest state for a predetermined period of time after discharging has ended, and the profile generation unit may be configured to generate the profile if the voltage value falls within a preset voltage range.

[0015] The voltage range may be set to a range in which a rate of decrease in resistance with an increase in voltage exceeds a preset critical value.

[0016] The profile generation unit may be configured to update the profile each time the data acquisition unit acquires the resistance value and the voltage value, and the control unit may be configured to set the reference range each time the profile is updated.

[0017] The control unit may be configured to diagnose the occurrence of an abnormality in the battery based on whether or not the resistance value exceeds the reference range.

[0018] The control unit may be configured to diagnose that no abnormality has occurred in the battery when the resistance value falls within the reference range, and to diagnose that an abnormality has occurred in the battery when the resistance value exceeds the reference range.

[0019] The control unit may be configured to generate an alarm corresponding to the occurrence of an abnormality when it is diagnosed that an abnormality has occurred in the battery.

[0020] A battery pack according to another aspect of the present invention includes a battery diagnostic device according to an aspect of the present invention.

[0021] A battery diagnosis method according to yet another aspect of the present invention includes a battery information acquisition step of acquiring a resistance value and a voltage value of a battery, a profile generation step of generating a profile indicating a correspondence relationship between the resistance value and the voltage value of the battery acquired in the battery information acquisition step, a reference range setting step of setting a reference range in the profile generated in the profile generation step, and a battery diagnosis step of diagnosing an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range. Effect of the Invention

[0022] According to an aspect of the present invention, the state of a battery can be diagnosed in a non-destructive manner through profile analysis, and in particular, the occurrence of an abnormality in the battery can be specifically diagnosed using the resistance and potential values ​​of the battery.

[0023] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0024] The following drawings attached to this specification, together with the detailed description of the invention described below, serve to further understand the technical ideas of the present invention, and the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0025] [Figure 1] 1 is a diagram illustrating a battery diagnostic device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic diagram illustrating a profile according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic diagram illustrating a reference line according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating a reference range according to an embodiment of the present invention. [Diagram 5] FIG. 13 is a schematic diagram illustrating another profile according to an embodiment of the present invention. [Figure 6] FIG. 13 is a schematic diagram illustrating yet another profile according to an embodiment of the present invention. [Figure 7] FIG. 2 is a schematic diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 8] 13 is a diagram illustrating a battery diagnostic method according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The terms and words used in this specification and the claims should not be interpreted limited to their ordinary and dictionary meanings, but should be interpreted in a meaning and concept that corresponds to the technical idea of ​​the present invention, based on the principle that the inventor himself can appropriately define the concept of the term in order to explain the invention in the best possible way.

[0027] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0028] In addition, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may make the gist of the present invention unclear, the detailed description will be omitted.

[0029] Terms including ordinal numbers such as first, second, etc. are used to distinguish one of various components from other components, and are not intended to limit the components.

[0030] Throughout the specification, when a part "comprises" a certain element, this does not mean to exclude other elements, but means that it may further include other elements, unless otherwise specified.

[0031] Furthermore, throughout this specification, when a part is referred to as being "connected" to another part, this includes not only a "direct connection" but also an "indirect connection" through other elements.

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0033] FIG. 1 is a diagram illustrating a battery diagnostic device 100 according to an embodiment of the present invention.

[0034] Referring to FIG. 1, a battery diagnostic device 100 according to an embodiment of the present invention may include a data acquisition unit 110, a profile generation unit 120, and a control unit .

[0035] The data acquisition unit 110 can acquire the resistance value and the voltage value of the battery.

[0036] Here, the term "battery" refers to an independent cell that has a negative terminal and a positive terminal and can be physically separated. As an example, a lithium ion cell or a lithium polymer cell may be considered as a battery. The term "battery" may also refer to a battery module in which a plurality of cells are connected in series and / or parallel. The term "battery" may also refer to a battery pack 1 in which a plurality of battery modules are connected in series and / or parallel. In the following description, for convenience of explanation, the term "battery" will be described as meaning one battery cell.

[0037] For example, the data acquisition unit 110 may acquire battery information about the voltage value and resistance value of the battery in real time. As another example, the data acquisition unit 110 may acquire battery information about the voltage value and resistance value of the battery periodically and / or non-periodically.

[0038] According to an embodiment, the data acquiring unit 110 may acquire battery information including a resistance value and a voltage value measured through a voltage sensing line connected to a positive electrode and a negative electrode of the battery. The data acquiring unit 110 may also be connected to a current sensor that measures a current of the battery. The data acquiring unit 110 may then acquire the battery information from the current sensor through the current sensing line. The data acquiring unit 110 may acquire the resistance value and the voltage value of the battery using information included in the battery information.

[0039] According to an embodiment, the data acquiring unit 110 may be configured to be able to communicate with an external device, and may receive battery information including a voltage value and a resistance value of the battery from an external device via communication.

[0040] In one embodiment, the data acquisition unit 110 may acquire the voltage value and resistance value at a time when the battery has been kept in a rest state for a predetermined time after the battery discharge has been completed. That is, the data acquisition unit 110 may acquire the voltage value and resistance value of the battery at a time when the battery has been kept in a rest state for a predetermined time after the battery discharge has been completed.

[0041] The profile generating unit 120 and the data acquiring unit 110 may be connected to each other via a wired and / or wireless connection so as to be able to communicate with each other. The profile generating unit 120 may receive battery information including resistance and voltage values ​​from the data acquiring unit 110 via a wired and / or wireless communication network.

[0042] The profile generator 120 may generate a profile using the resistance value and the voltage value of the battery acquired by the data acquirer 110. Here, the profile may indicate the correspondence relationship between the resistance value and the voltage value of the battery.

[0043] For example, the profile may be represented by a two-dimensional XY graph, where the X-axis is the voltage value of the battery and the Y-axis is the resistance value of the battery, as will be described in detail below with reference to FIG.

[0044] 2 is a schematic diagram of a profile according to an embodiment of the present invention, showing an XY two-dimensional graph in which the X-axis is set to the voltage value of the battery and the Y-axis is set to the resistance value of the battery.

[0045] At least one of the voltage value and the resistance value on the profile generated by the profile generating unit 120 may be a relative value, for example, at least one of the voltage value and the resistance value may be a normalized value.

[0046] For example, in the embodiment of FIG. 2, the X-axis shows absolute voltage values, while the Y-axis shows normalized relative resistance values.

[0047] In one embodiment, the profile generator 120 may generate a profile if the voltage value falls within a preset voltage interval. The voltage interval may be set based on a specific voltage value or based on a resistance decrease rate.

[0048] An embodiment of a voltage section will now be described. The voltage section may be set based on whether a rate of decrease in resistance with an increase in voltage exceeds a preset critical value. In this case, the profile generator 120 may generate a profile if the rate of decrease in resistance with an increase in voltage belongs to a section that exceeds a preset critical value.

[0049] Referring to FIG. 2, in the voltage range of 3.5V or less, the resistance decreases rapidly as the voltage increases. Therefore, the profile generator 120 can generate a profile if the voltage value is in the range of 3.5V or less.

[0050] For example, in the embodiment of FIG. 2, the resistance decrease rate in a voltage range where the voltage value exceeds 3.5V may be equal to or less than a preset critical value. Here, the resistance decrease rate is a rate of change in resistance with respect to voltage, and refers to the rate at which resistance decreases as the voltage increases. That is, in a voltage range above 3.5V, the rate at which resistance decreases with an increase in voltage may be equal to or less than the critical value, and in a voltage range below 3.5V, the rate at which resistance decreases with an increase in voltage may exceed the critical value. Therefore, the profile generator 120 may generate a profile for a voltage range below 3.5V.

[0051] Another embodiment of the voltage interval will be described. The voltage interval may be set based on a reference voltage value preset for a reference battery. Specifically, a reference profile indicating a correspondence relationship between the reference voltage value and the reference resistance value may be prepared in advance. A resistance value obtained by adding a predetermined resistance value to the minimum resistance value in the reference profile may be determined as the target resistance value. For example, the predetermined resistance value may be set to a resistance value of 0.1 Ω or less. Preferably, the predetermined resistance value may be preset to a resistance value of 0.05 Ω or less.

[0052] For example, if the minimum resistance value is LR (Ω) and the predetermined resistance value is 0.05Ω, the target resistance value is LR+0.05Ω.

[0053] Then, a voltage value corresponding to the target resistance value may be set as the reference voltage value. Here, if there are multiple voltage values ​​corresponding to the target resistance value, the lowest voltage value among the multiple voltage values ​​may be set as the reference voltage value. For example, in the embodiment of FIG. 2, the reference voltage value may be preset to 3.5V. Thus, the profile generator 120 may generate a profile for a voltage section of 3.5V or less.

[0054] Further embodiments of the voltage interval will be described. The voltage interval may be set based on the voltage profile and the differential profile of a reference battery. Here, the voltage profile is a profile showing the correspondence between the voltage (V) and the capacity (Q) of the reference battery. For example, the voltage profile may be represented by a two-dimensional graph with the X-axis set to capacity (Q) and the Y-axis set to voltage (V). And, the differential profile is a profile showing the correspondence between the differential voltage (dVdQ) and the capacity (Q) of the reference battery. For example, the differential profile is the first derivative of the voltage profile. That is, the differential profile may be represented by a two-dimensional graph with the X-axis set to capacity (Q) and the Y-axis set to differential voltage (dVdQ) obtained by differentiating voltage (V) with respect to capacity (Q).

[0055] Specifically, the voltage section may be set to a section obtained by excluding a voltage section corresponding to a negative plateau section in which the influence of the negative electrode of the battery is minimized from the entire voltage section, i.e., the voltage section may be set to a section equal to or lower than a reference voltage value corresponding to the start capacity of the negative plateau section from the entire voltage section.

[0056] In the following, the capacity is described as a normalized value between 0 and 1. The differential profile may include a negative plateau section that is less affected by the negative electrode. For example, the differential profile may include a plurality of peaks (points that are convex toward the top). Such a plurality of peaks may include a peak (hereinafter, a target peak) in which the capacity (Q) belongs to a capacity section of 0.4 to 1 and the differential voltage (dVdQ) is maximum. If the capacity of the target peak is Qt, the capacity Qt of the target peak may be the start capacity of the negative plateau section. That is, the capacity section in which the capacity (Q) is Qt to 1 may be the negative plateau section. Then, the voltage value Vt corresponding to the capacity Qt in the voltage profile may be set as the reference voltage value. Thus, the section below the reference voltage value Vt in the entire voltage section may be set as the voltage section. The control unit 130 may set a reference range in the profile received from the profile generating unit 120. The reference range may mean a range of resistance values ​​that indicates that the rate of change of the resistance value with respect to the voltage value of the battery is normal. A method of setting the reference range will be described later.

[0057] The control unit 130 may diagnose the occurrence of an abnormality in the battery based on the result of comparing the resistance value of the battery with the reference range, as will be described later with reference to FIG.

[0058] The battery diagnostic device 100 according to an embodiment of the present invention can specifically diagnose an abnormality in the battery by comparing the resistance value of the battery with a reference range.

[0059] The battery diagnostic device 100 according to an embodiment of the present invention can accurately diagnose the state of a battery by generating a profile using voltage and resistance values ​​measured in real time.

[0060] Meanwhile, the data acquisition unit 110, the profile generation unit 120, and the control unit 130 included in the battery diagnostic device 100 may selectively include a processor, an ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art, to execute various control logics performed in the present invention. Also, when the control logic is embodied as software, the data acquisition unit 110, the profile generation unit 120, and the control unit 130 may be embodied as a collection of program modules. In this case, the program modules may be stored in a memory and executed by the data acquisition unit 110, the profile generation unit 120, and the control unit 130. The memory may be provided inside or outside the data acquisition unit 110, the profile generation unit 120, and the control unit 130, respectively, and may be connected to the data acquisition unit 110, the profile generation unit 120, and the control unit 130 by various known means.

[0061] The battery diagnostic device 100 may further include a recording unit 140. The recording unit 140 may store data and programs necessary for each component of the battery diagnostic device 100 to operate and function, or data generated in the process of operating and functioning. The recording unit 140 is not particularly limited in type as long as it is a known information recording means known to be capable of recording, erasing, updating and reading data. As an example, the information recording means may include a RAM, a flash memory, a ROM, an EEPROM, a register, etc. The recording unit 140 may also store a program code in which a process executable by the control unit 130 is defined.

[0062] Hereinafter, the reference range will be described in detail with reference to Fig. 3. The reference range may refer to a range indicating that the rate of change of the resistance value of the battery is normal.

[0063] 3 is a schematic diagram illustrating a reference line according to an embodiment of the present invention, in which the reference line is shown in an XY two-dimensional graph in which the X-axis is set to the voltage value of the battery and the Y-axis is set to the resistance value of the battery.

[0064] In one embodiment, the control unit 130 may set a reference line indicating a rate of change of the resistance value with respect to the voltage value in the profile. For example, the control unit 130 may set the reference line by approximating a curve connecting each resistance value from a profile indicating the resistance value with respect to the voltage value.

[0065] In one embodiment, multiple reference lines may be set from one profile according to the rate of change of the resistance value. For example, the controller 130 may set multiple reference lines from one profile based on a point where the rate of change of the resistance value changes abruptly.

[0066] 3, the control unit 130 may set two reference lines based on a point (A) where the rate of change of the resistance value changes abruptly. The control unit 130 may generate a first reference line L1 in a section below the point (A) where the rate of change of the resistance value changes abruptly, and may generate a second reference line L2 in a section above the point (A).

[0067] In the embodiment of FIG. 3, the first reference line L1 and the second reference line L2 are shown to be located in the +Y-axis direction from the profile, but the first reference line L1 and the second reference line L2 may overlap the profile. For example, in the embodiment of FIG. 3, the first reference line L1 may move in the -Y-axis direction to overlap the section below point (A) of the profile. Also, the second reference line L2 may move in the -Y-axis direction to overlap the section above point (A). Specifically, the reference line may be derived as a linear relational equation for points included in the corresponding section (e.g., the section below point (A) or the section above point (A)). Therefore, the reference line may overlap the profile, and the embodiment of FIG. 3 shows the reference line and the profile separately for convenience of explanation. That is, in the drawings (FIGS. 3 to 6) of the present application, the profile and the first reference line L1 and the second reference line L2 are shown separated from each other, but it should be noted that this is for convenience of explanation.

[0068] The control unit 130 sets the reference lines according to the rate of change of the resistance value, so that the battery resistance abnormality can be determined for each voltage, and the battery abnormality can be diagnosed more accurately.

[0069] In one embodiment, the controller 130 may set the baseline excluding the target resistance value and the target voltage value, which may refer to the resistance value and the voltage value most recently included in the profile.

[0070] The control unit 130 sets a reference line excluding the target resistance value and the target voltage value, and can accurately diagnose an abnormality in the battery by comparing the target resistance value with the reference line in real time.

[0071] Here, the reference line may be updated every time the voltage value and resistance value of the battery are measured. For example, assume that the nth resistance value is a target resistance value and the nth voltage value is a target voltage value at the nth time point. At the nth time point, the reference line may be set based on the 1st to n-1th resistance values ​​and the 1st to n-1th voltage values. Then, at the n+1th time point, the n+1th resistance value may be set to the target resistance value and the n+1th voltage value may be set to the target voltage value. In this case, the reference line may be updated based on the 1st to nth resistance values ​​and the 1st to nth voltage values.

[0072] That is, the battery diagnostic device 100 has an advantage in that the battery state can be diagnosed more accurately by updating the reference line to reflect the latest battery state information.

[0073] The control unit 130 may set a reference range based on the reference line, as will be described with reference to FIG.

[0074] 4 is a schematic diagram illustrating a reference range according to an embodiment of the present invention, in which the reference range is shown in an XY two-dimensional graph with the X-axis representing the voltage value of the battery and the Y-axis representing the resistance value of the battery.

[0075] In one embodiment, the control unit 130 may set the reference range based on the baseline. For example, the control unit 130 may set the reference range to be within a predetermined critical value from the baseline.

[0076] Referring to FIG. 4, the controller 130 may set a reference range (B) within a predetermined threshold value (th) from the reference line L2.

[0077] Here, the critical value (th) is a value added to set a reference range from the reference line. In other words, the critical value (th) is a reference value that determines a normal margin range for the resistance value. That is, the range from the reference line to the critical value (th) is set as the reference range (B) in which the battery can be diagnosed as being in a normal state.

[0078] For example, the critical value (th) may be preset to a resistance value of 1 Ω or less. Preferably, the critical value (th) may be preset to a resistance value of 0.5 Ω or less.

[0079] For example, the critical value (th) may be determined to be an optimal value through experiments using batteries in various states. As another example, the critical value (th) may be set taking into consideration a measurement error for a voltage value. That is, a measured voltage value may include a measurement error due to noise. Since a voltage measurement error affects a calculated resistance value, the critical value (th) may be set taking into consideration such a voltage measurement error. That is, the critical value (th) may be set to prevent a battery state from being erroneously diagnosed due to a voltage measurement error.

[0080] The control unit 130 sets the reference range to within a predetermined critical value from the reference line, thereby preventing abnormal diagnosis due to a slight error occurring in the process of acquiring the resistance value and voltage value of the battery.

[0081] In one embodiment, the control unit 130 may set the reference range based on a plurality of reference lines. For example, the control unit 130 may set the reference range based on a plurality of reference lines set for each section in which the rate of change of the resistance value changes rapidly.

[0082] 4, a reference range is shown which is set based on a number of reference lines which are expressed based on a point (A) where the rate of change of the resistance value changes abruptly. The control unit 130 may set the reference range from a first reference line L1 to a critical value (th) or less in a section where the resistance value is equal to or less than the point (A) and may set the reference range from a second reference line L2 to a critical value (th) or less in a section where the resistance value is equal to or more than the point (A).

[0083] Since the control unit 130 sets the reference range based on different reference lines set based on the point (A) where the rate of change of the resistance value changes abruptly, the abnormality diagnosis based on the resistance value of the battery can be performed more accurately.

[0084] Hereinafter, a configuration in which the control unit 130 determines whether an abnormality has occurred in the battery by using the reference range will be described with reference to FIG.

[0085] 5 is a schematic diagram of another profile according to an embodiment, showing an XY two-dimensional graph with the X-axis representing the voltage value of the battery and the Y-axis representing the resistance value of the battery.

[0086] In one embodiment, the controller 130 may diagnose the occurrence of an abnormality in the battery based on whether a voltage value belongs to a voltage range and a resistance value corresponding to the voltage value exceeds a reference range.

[0087] In one embodiment, if it is determined that an abnormality has occurred in the battery, the control unit 130 may generate an alarm corresponding to the occurrence of the abnormality.

[0088] Referring to FIG. 5, the control unit 130 may diagnose that an abnormality has occurred in the battery depending on whether the resistance value exceeds Section B, which is a reference range.

[0089] For example, if the resistance value falls within the reference range, the control unit 130 may diagnose that the battery is not abnormal. Conversely, if the resistance value exceeds the reference range, the control unit 130 may diagnose that the battery is abnormal. Here, the voltage value corresponding to the resistance value may fall within a voltage range.

[0090] Referring to FIG. 5, the control unit 130 may diagnose that no abnormality occurs in the battery since the first resistance value R1 belongs to section B, which is the reference range.

[0091] However, since the second resistance value R2 exceeds the section B of the reference range, the control unit 130 may diagnose that an abnormality has occurred in the battery.

[0092] The control unit 130 diagnoses an abnormality using the result of comparing the resistance value with the reference range, making it possible to diagnose the battery condition in a non-destructive manner.

[0093] 6 is a schematic diagram showing yet another profile according to an embodiment of the present invention, specifically, a profile updated each time the data acquisition unit 110 acquires resistance values ​​and voltage values.

[0094] In one embodiment, the profile generator 120 may update the profile every time the data acquirer 110 acquires a resistance value and a voltage value. For example, the profile generator 120 may update the profile every time the data acquirer 110 acquires a resistance value and a voltage value if the acquired voltage value belongs to a preset voltage interval. The voltage interval may be set on the condition of a specific voltage value or on the condition of a resistance decrease rate.

[0095] For example, the voltage section may be set to a section where a rate of decrease in resistance with an increase in voltage exceeds a preset critical value. In this case, the profile generator 120 may generate a profile if the rate of decrease in resistance with an increase in voltage belongs to a section where the rate of decrease in resistance with an increase in voltage exceeds a preset critical value.

[0096] Referring to FIG. 6, since the resistance decreases rapidly as the voltage increases in the range of voltage values ​​below 3.5V, the profile generating unit 120 may update the profile if the acquired voltage value is in the range of 3.5V or less.

[0097] In one embodiment, the control unit 130 may set a reference range every time the profile is updated. For example, the control unit 130 may set a reference line every time the profile is updated, and set a reference range based on the set reference line. Setting of the reference line has been described above, and therefore will not be described here.

[0098] 6, it can be seen that the control unit 130 has newly set the reference range from C to D according to the updated profile.

[0099] The control unit 130 updates the profile in real time and sets a new reference range based on the profile, so that abnormalities due to resistance values ​​can be diagnosed in real time.

[0100] The battery diagnostic device 100 according to the present invention may be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the above-mentioned battery diagnostic device 100. In this configuration, at least a part of the components of the battery diagnostic device 100 may be implemented by complementing or adding functions of components included in a conventional BMS. For example, the data acquisition unit 110, the profile generation unit 120, the control unit 130, and the recording unit 140 of the battery diagnostic device 100 may be implemented as components of the BMS.

[0101] FIG. 7 is a diagram illustrating an exemplary configuration of a battery pack 1 including a battery diagnostic device 100 according to another embodiment of the present invention.

[0102] Furthermore, the battery diagnostic device 100 according to the present invention may be provided in a battery pack 1. That is, the battery pack 1 according to the present invention may include the above-mentioned battery diagnostic device 100, a measuring unit 200, a charging / discharging unit 300, and one or more battery cells. Furthermore, the battery pack 1 may further include electrical components (e.g., relays, fuses, etc.), a case, etc.

[0103] The positive terminal of battery B may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery B may be connected to the negative terminal P− of battery pack 1.

[0104] The measurement unit 200 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measurement unit 200 may be connected to a positive terminal of the battery B via the first sensing line SL1 and to a negative terminal of the battery B via the second sensing line SL2. The measurement unit 200 may measure the voltage of the battery B based on the voltages measured in the first sensing line SL1 and the second sensing line SL2, respectively.

[0105] The measurement unit 200 may be connected to the current measurement unit A via a third sensing line SL3. For example, the current measurement unit A may be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery B. The measurement unit 200 may measure the charging current of the battery B via the third sensing line SL3 to calculate the charged amount. The measurement unit 200 may also measure the discharging current of the battery B via the third sensing line SL3 to calculate the discharged amount.

[0106] One end of the charging / discharging unit 300 may be connected to the positive terminal P+ of the battery pack 1, and the other end may be connected to the negative terminal P- of the battery pack 1. Therefore, the positive terminal of battery B, the positive terminal P+ of battery pack 1, the charging / discharging unit 300, the negative terminal P- of battery pack 1, and the negative terminal of battery B may be electrically connected to each other.

[0107] FIG. 8 is a diagram illustrating a battery diagnostic method according to still another embodiment of the present invention.

[0108] Preferably, each step of the battery diagnostic method may be performed by the battery diagnostic device 100. In the following, the contents overlapping with the above description will be omitted or will be briefly described.

[0109] The battery information acquisition step S110 is a step of acquiring a resistance value and a voltage value of the battery, and may be performed by the data acquisition unit 110.

[0110] For example, the data acquiring unit 110 may acquire battery information regarding a voltage value and a resistance value of the battery in real time. According to an embodiment, the data acquiring unit 110 may acquire battery information including a resistance value and a voltage value measured through a voltage sensing line connected to a positive electrode and a negative electrode of the battery. The data acquiring unit 110 may also be connected to a current sensor that measures a current of the battery. The data acquiring unit 110 may then acquire the battery information from the current sensor through the current sensing line. The data acquiring unit 110 may acquire the resistance value and the voltage value of the battery using information included in the battery information.

[0111] According to an embodiment, the data acquisition unit 110 may be configured to be able to communicate with an external device, and may receive battery information including a voltage value and a resistance value of the battery from an external device via communication.

[0112] In one embodiment, the data acquisition unit 110 may acquire the voltage value and resistance value at a time when the battery has been in a rest state for a predetermined time after the battery has been discharged. That is, the data acquisition unit 110 may acquire the voltage value and resistance value of the battery at a time when the battery has been in a rest state for a predetermined time after the battery has been discharged.

[0113] The profile generating step S120 is a step of generating a profile indicating a correspondence relationship between the resistance value and the voltage value of the battery acquired in the battery information acquiring step S110, and may be performed by the profile generating unit 120.

[0114] For example, the profile generating unit 120 and the data acquiring unit 110 may be connected to each other via a wired and / or wireless connection so as to be able to communicate with each other, and the profile generating unit 120 may receive battery information including resistance and voltage values ​​from the data acquiring unit 110 via a wired and / or wireless communication network.

[0115] The profile generator 120 may generate a profile using the resistance value and the voltage value of the battery acquired by the data acquirer 110. Here, the profile may indicate the correspondence relationship between the resistance value and the voltage value of the battery.

[0116] For example, the profile may be represented by an XY two-dimensional graph where the X-axis is set to the voltage value of the battery and the Y-axis is set to the resistance value of the battery.

[0117] In one embodiment, the profile generator 120 may generate a profile if the voltage value falls within a preset voltage interval. The voltage interval may be set based on a specific voltage value or a resistance decrease rate.

[0118] For example, the voltage section may be set to a section where a rate of decrease in resistance with an increase in voltage exceeds a preset critical value. In this case, the profile generator 120 may generate a profile if the rate of decrease in resistance with an increase in voltage belongs to a section where the rate of decrease in resistance with an increase in voltage exceeds a preset critical value.

[0119] The reference range setting step S130 is a step of setting a reference range in the profile generated in the profile generating step, and may be performed by the control unit 130.

[0120] The control unit 130 may set a reference range in the profile received from the profile generating unit 120. The reference range may refer to a range indicating that the rate of change of the resistance value of the battery is normal.

[0121] For example, the control unit 130 may set a reference range based on a reference line. In one embodiment, the control unit 130 may set a reference line that indicates a rate of change of a resistance value relative to a voltage value in a profile. For example, the control unit 130 may set a reference line by approximating a curve that connects each resistance value in a profile in which resistance values ​​relative to voltage values ​​are displayed.

[0122] In one embodiment, multiple reference lines may be set from one profile according to the rate of change of the resistance value. For example, the controller 130 may set multiple reference lines from one profile based on a point where the rate of change of the resistance value changes abruptly.

[0123] In one embodiment, the control unit 130 may set the reference range to within a predetermined critical value from the baseline. For example, the control unit 130 may estimate a predetermined critical value from the baseline and set the reference range to within the predetermined critical value.

[0124] The control unit 130 sets the reference range to within a predetermined critical value from the reference line, thereby preventing abnormal diagnosis due to a slight error occurring in the process of acquiring the resistance value and voltage value of the battery.

[0125] In one embodiment, the control unit 130 may set the reference range based on a plurality of reference lines. For example, the control unit 130 may set the reference range based on a plurality of reference lines set for each section in which the rate of change of the resistance value changes rapidly.

[0126] Since the control unit 130 sets the reference range based on different reference lines set based on the point where the rate of change of the resistance value changes abruptly, the abnormality diagnosis based on the resistance value of the battery can be performed more accurately.

[0127] The battery diagnosis step S140 is a step of diagnosing the occurrence of an abnormality in the battery based on a result of comparing the resistance value of the battery with a reference range, and may be performed by the control unit 130.

[0128] In one embodiment, the control unit 130 may diagnose the occurrence of an abnormality in the battery based on whether the resistance value exceeds a reference range. For example, if the resistance value falls within the reference range, the control unit 130 may diagnose that no abnormality has occurred in the battery. Conversely, if the resistance value exceeds the reference range, the control unit 130 may diagnose that an abnormality has occurred in the battery.

[0129] The control unit 130 diagnoses an abnormality using the result of comparing the resistance value with a reference range, thereby making it possible to diagnose the state of the battery in a non-destructive manner.

[0130] The battery diagnostic device 100 according to an embodiment of the present invention can specifically diagnose an abnormality in the battery by comparing the resistance value of the battery with a reference range.

[0131] The battery diagnostic device 100 according to an embodiment of the present invention can accurately diagnose the state of a battery by generating a profile using voltage and resistance values ​​measured in real time.

[0132] The above-described embodiments of the present invention may be embodied not only by an apparatus and a method, but also through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by a person skilled in the art from the description of the above-described embodiments.

[0133] As described above, the present invention has been described using limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical spirit of the present invention and the equivalent scope of the claims.

[0134] Furthermore, the present invention described above is susceptible to various substitutions, modifications and alterations by a person having ordinary knowledge in the technical field to which the present invention belongs, within the scope that does not deviate from the technical concept of the present invention, and is not limited to the above-described embodiments and the accompanying drawings, but may be configured by selectively combining all or part of each embodiment for various modifications. [Explanation of symbols]

[0135] 1: Battery pack 100: Battery diagnostic device 110: Data acquisition section 120: Profile generation unit 130: Control unit 140: Recording section 200: Measuring part 300: Charge / discharge section

Claims

1. a data acquisition unit configured to acquire a resistance value and a voltage value of the battery; a profile generating unit configured to generate a profile indicating a correspondence relationship between a resistance value and a voltage value of the battery acquired by the data acquiring unit; a control unit configured to set a reference range using a profile received from the profile generation unit, and to diagnose an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range.

2. The control unit is 2 . The battery diagnostic device according to claim 1 , further comprising: a reference line indicating a rate of change of the resistance value relative to the voltage value in the profile; and a reference range set based on the reference line.

3. The control unit is The battery diagnostic device according to claim 2 , wherein the reference range is set to within a predetermined critical value from the reference line.

4. The control unit is The battery diagnostic device according to claim 2 , configured to set the baseline excluding a target resistance value and a target voltage value most recently included in the profile.

5. The data acquisition unit is The method is configured to obtain the voltage value and the resistance value at a time when the battery has been kept in a rest state for a predetermined period of time after the discharge of the battery has been completed, The profile generation unit includes: The battery diagnostic device of claim 1 , further comprising: a voltage detection unit configured to detect a voltage value of the battery and generate the profile when the voltage value falls within a preset voltage range.

6. The voltage section is 6. The battery diagnostic device according to claim 5, wherein a rate of decrease in resistance with an increase in voltage is set to a range exceeding a preset critical value.

7. The profile generation unit includes: The profile is updated every time the data acquisition unit acquires the resistance value and the voltage value, The control unit is The battery diagnostic device according to claim 1 , configured to set the reference range every time the profile is updated.

8. The control unit is The battery diagnostic device according to claim 1 , configured to diagnose the occurrence of an abnormality in the battery based on whether or not the resistance value exceeds the reference range.

9. The control unit is 9. The battery diagnostic device according to claim 8, configured to diagnose that no abnormality has occurred in the battery when the resistance value is within the reference range, and to diagnose that an abnormality has occurred in the battery when the resistance value exceeds the reference range.

10. The control unit is The battery diagnostic device according to claim 1 , configured to generate an alarm corresponding to the occurrence of an abnormality when it is diagnosed that an abnormality has occurred in the battery.

11. A battery pack comprising the battery diagnostic device according to any one of claims 1 to 10.

12. A battery information acquisition step of acquiring a resistance value and a voltage value of a battery; a profile generating step of generating a profile indicating a correspondence relationship between a resistance value and a voltage value of the battery acquired in the battery information acquiring step; a reference range setting step of setting a reference range based on the profile generated in the profile generating step; and diagnosing an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range.

Images