Battery diagnostic device and method

Abstract

This invention provides a battery diagnostic device and method that can diagnose the state of a battery in a non-destructive manner through profile analysis. [Solution] A battery diagnostic device according to one embodiment of the present invention includes: a data acquisition unit configured to acquire the resistance value and voltage value of a battery; a profile generation unit configured to generate a profile showing the correspondence between the resistance value and voltage value of the battery acquired by the data acquisition unit; and a control unit configured to set a reference range with the profile received from the profile generation unit and to 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.

Description

Technical Field

[0001] This application claims priority based on 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, and all the contents disclosed in the specifications and drawings of the applications are incorporated into this application.

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

Background Art

[0003] In recent years, the demand for portable electronic products such as notebooks, video cameras, and mobile phones has rapidly increased, and as the development of electric vehicles, energy storage batteries, robots, artificial satellites, etc. has become full-scale, research on high-performance batteries that can be repeatedly charged and discharged has been actively conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries are attracting attention because they have almost no memory effect compared to nickel-based batteries, can be freely charged and discharged, have a very low self-discharge rate, and have a high energy density.

[0005] Such batteries deteriorate while being repeatedly charged and discharged. For example, the gas generation inside the battery can reduce the electron transfer ability in the electrode, and uneven negative electrode deterioration may occur.

[0006] In addition, the housing of the battery may bulge due to the gas inside the battery, and the sealing part of the battery may be vented. In this case, the gas inside the battery is released, which may lead to a battery fire.

[0007] In other words, if the battery condition is not diagnosed promptly, unexpected problems such as performance degradation, fire, and explosion may occur. [Overview of the project] [Problems that the invention aims to solve]

[0008] This invention was devised to solve the above-mentioned problems, and aims to provide a battery diagnostic device 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 be more clearly evident from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof 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 the resistance value and voltage value of a battery; a profile generation unit configured to generate a profile showing the correspondence between the resistance value and voltage value of the battery acquired by the data acquisition unit; and a control unit configured to set a reference range using the profile received from the profile generation unit and to 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.

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

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

[0013] The control unit may be configured to set the reference line excluding the target resistance value and target voltage value most recently included in the profile.

[0014] The data acquisition unit is configured to acquire the voltage value and resistance value at a predetermined time after the battery has finished discharging and has remained in a dormant state, and the profile generation unit may be configured to generate the profile if the voltage value falls within a preset voltage range.

[0015] The aforementioned voltage interval may be set to an interval in which the rate of decrease in resistance due to an increase in voltage exceeds a predetermined 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 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 whether or not the resistance value exceeds the reference range, thereby detecting an abnormality in the battery.

[0018] The control unit may be configured to diagnose that there is no abnormality in the battery if the resistance value falls within the reference range, and to diagnose that there is an abnormality in the battery if 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 in the battery if 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 one aspect of the present invention.

[0021] According to another aspect of the present invention, a battery diagnosis method includes a battery information acquisition step for acquiring a resistance value and a voltage value of a battery, a profile generation step for generating a profile showing 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 for setting a reference range based on the profile generated in the profile generation step, and a battery diagnosis step for diagnosing the occurrence of an abnormality in the battery based on a result of comparing the resistance value of the battery with the reference range.

Advantages of the Invention

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

[0023] The effects of the present invention are not limited to the above-described effects, 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 serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later, and the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0025] [Figure 1] It is a diagram schematically showing a battery diagnosis device according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing a profile according to an embodiment of the present invention. [Figure 3] It is a diagram schematically showing a reference line according to an embodiment of the present invention. [Figure 4] It is a diagram schematically showing a reference range according to an embodiment of the present invention. [Figure 5] It is a diagram schematically showing another profile according to an embodiment of the present invention. [Figure 6] This figure schematically shows yet another profile according to one embodiment of the present invention. [Figure 7] This figure schematically illustrates an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 8] This figure schematically illustrates a battery diagnostic method according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0026] Terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary and dictionary meanings, but rather in a manner and concept corresponding to the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of a term in order to best describe the invention.

[0027] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention. It should be understood that there are various equivalents and modifications that can be substituted for these at the time of filing this application.

[0028] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such detailed description will be omitted.

[0029] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of several components from others, and these terms do not limit the components themselves.

[0030] When a part of the specification "includes" a certain component, unless otherwise specified, this does not exclude other components, but rather means that it may include other components.

[0031] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only "direct connections" but also "indirect connections" mediated by other elements.

[0032] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0033] Figure 1 is a schematic diagram showing a battery diagnostic device 100 according to one embodiment of the present invention.

[0034] Referring to Figure 1, a battery diagnostic device 100 according to one embodiment of the present invention may include a data acquisition unit 110, a profile generation unit 120, and a control unit 130.

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

[0036] Here, "battery" refers to a single, physically separable, independent cell equipped with a negative terminal and a positive terminal. For example, a single lithium-ion cell or lithium polymer cell can be considered a battery. Alternatively, "battery" may refer to a battery module in which multiple cells are connected in series and / or parallel. Furthermore, "battery" may also refer to a battery pack 1 in which multiple battery modules are connected in series and / or parallel. For the sake of clarity, in the following explanation, "battery" will be used to refer to a single battery cell.

[0037] For example, the data acquisition unit 110 can acquire battery information regarding the battery's voltage and resistance in real time. As another example, the data acquisition unit 110 can acquire battery information regarding the battery's voltage and resistance periodically and / or aperiodically.

[0038] Depending on the embodiment, the data acquisition unit 110 may acquire battery information including resistance and voltage values ​​measured through voltage sensing lines connected to the positive and negative electrodes of the battery. The data acquisition unit 110 may also be connected to a current sensor that measures the battery current. The data acquisition unit 110 may then acquire battery information from the current sensor through the current sensing lines. The data acquisition unit 110 may then acquire the battery's resistance and voltage values ​​using the information contained in the battery information.

[0039] Depending on the embodiment, the data acquisition unit 110 may be configured to communicate with the outside. The data acquisition unit 110 may receive battery information, including the battery voltage and resistance values, from the outside using communication.

[0040] In one embodiment, the data acquisition unit 110 may acquire the voltage and resistance values ​​at a predetermined time after the battery has finished discharging and has remained in a dormant state. That is, the data acquisition unit 110 can acquire the voltage and resistance values ​​of the battery at a predetermined time after the battery has finished discharging and has remained in a dormant state.

[0041] The profile generation unit 120 and the data acquisition unit 110 can be connected to each other via wired and / or wireless connections to enable communication. The profile generation unit 120 can then receive battery information, including resistance and voltage values, from the data acquisition unit 110 via a wired and / or wireless communication network.

[0042] The profile generation unit 120 can generate a profile using the battery resistance and voltage values ​​acquired by the data acquisition unit 110. Here, the profile may show the correspondence between the battery resistance and voltage values.

[0043] For example, a profile can be represented as a two-dimensional XY graph, where the X-axis is set to the battery voltage and the Y-axis to the battery resistance. See Figure 2 for further details.

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

[0045] At least one of the voltage and resistance values ​​in the profile generated by the profile generation unit 120 may be a relative value. For example, at least one of the voltage and resistance values ​​may be a normalized value.

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

[0047] In one embodiment, the profile generation unit 120 can 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 reduction rate.

[0048] One embodiment of a voltage interval will be described. A voltage interval can be defined based on whether the rate of decrease in resistance due to an increase in voltage exceeds a preset critical value. In this case, the profile generation unit 120 can generate a profile if the interval falls within the range where the rate of decrease in resistance due to an increase in voltage exceeds a preset critical value.

[0049] Referring to Figure 2, in the voltage range of 3.5V or less, the resistance decreases rapidly as the voltage increases. Therefore, the profile generation unit 120 can generate a profile if the voltage value falls within the range of 3.5V or less.

[0050] For example, in the embodiment shown in Figure 2, the resistance reduction rate in voltage ranges where the voltage value exceeds 3.5V may be less than or equal to a preset critical value. Here, the resistance reduction rate is the rate of change of resistance with respect to voltage, meaning the ratio by which resistance decreases as the voltage increases. That is, in voltage ranges exceeding 3.5V, the ratio of resistance reduction with increasing voltage is less than or equal to the critical value, while in voltage ranges below 3.5V, the ratio of resistance reduction with increasing voltage may exceed the critical value. Therefore, the profile generation unit 120 can generate a profile for voltage ranges below 3.5V.

[0051] Other embodiments of the voltage interval will be described. The voltage interval may be set based on a preset reference voltage value relative to a reference battery. Specifically, a reference profile showing the correspondence between the reference voltage value and the reference resistance value may be prepared in advance. The 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 is LR(Ω) and the given resistance is 0.05Ω, then the target resistance is LR+0.05Ω.

[0053] Then, a voltage value corresponding to the target resistance value can 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 ​​can be set as the reference voltage value. For example, in the embodiment shown in Figure 2, the reference voltage value can be preset to 3.5V. Therefore, the profile generation unit 120 can generate a profile for voltage intervals 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 differential profile of a reference battery. Here, the voltage profile is a profile showing the correspondence between the voltage (V) and 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). The differential profile is a profile showing the correspondence between the differential voltage (dVdQ) and 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 the differential voltage (dVdQ) obtained by differentiating voltage (V) with respect to capacity (Q).

[0055] Specifically, the voltage interval can be set to the interval obtained by subtracting the voltage interval corresponding to the negative electrode flat section where the influence of the battery's negative electrode is minimized from the overall voltage interval. In other words, the voltage interval can be set to an interval below the reference voltage value corresponding to the starting capacity of the negative electrode flat section from the overall voltage interval.

[0056] In the following, capacity is described as a normalized value between 0 and 1. The differential profile may include a negative electrode flat section that is less affected by the negative electrode. For example, the differential profile may include multiple peaks (points that are convex upwards). Among these multiple peaks, there may be a peak (hereinafter referred to as the target peak) that belongs to a capacity section where the capacity (Q) is between 0.4 and 1 and where the differential voltage (dVdQ) is maximum. If the capacity of the target peak is Qt, then the capacity Qt of the target peak may be the starting capacity of the negative electrode flat section. That is, a capacity section where the capacity (Q) is between Qt and 1 may be the negative electrode flat section. Then, the voltage value Vt corresponding to the capacity Qt in the voltage profile may be set as the reference voltage value. Therefore, in the overall voltage section, a section below the reference voltage value Vt may be set as the voltage section. The control unit 130 may set a reference range with the profile received from the profile generation 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 battery voltage value is normal. The method for setting the reference range will be described later.

[0057] The control unit 130 can diagnose a battery malfunction based on a comparison of the battery's resistance value with a reference range. This will be explained later with reference to Figure 3.

[0058] A battery diagnostic device 100 according to one embodiment of the present invention can specifically diagnose battery abnormalities by comparing the battery's resistance value with a reference range.

[0059] A battery diagnostic device 100 according to one 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 from the battery.

[0060] On the other hand, the data acquisition unit 110, profile generation unit 120, and control unit 130 provided in the battery diagnostic device 100 may selectively include processors, ASICs (Application-Specific Integrated Circuits), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is embodied as software, the data acquisition unit 110, profile generation unit 120, and control unit 130 may be embodied as a collection of program modules. In this case, the program modules are stored in memory and can be executed by the data acquisition unit 110, profile generation unit 120, and control unit 130. The memory may be provided inside or outside the data acquisition unit 110, profile generation unit 120, and control unit 130, respectively, and can be connected to the data acquisition unit 110, profile generation unit 120, and control unit 130 by various well-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 during the process of operation 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 able to record, erase, update, and read data. Examples of information recording means may include RAM, flash® memory, ROM, EEPROM, registers, etc. The recording unit 140 may also store program code that defines processes that can be executed by the control unit 130.

[0062] The reference range will be explained in detail below with reference to Figure 3. The reference range can mean the range in which the rate of change of the battery's resistance value is considered normal.

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

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

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

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

[0067] The embodiment in Figure 3 shows that the first reference line L1 and the second reference line L2 are located in the +Y axis direction relative to the profile, but the first reference line L1 and the second reference line L2 may overlap with the profile. For example, in the embodiment of Figure 3, the first reference line L1 may move in the -Y axis direction and overlap with the section of the profile below point (A). Similarly, the second reference line L2 may also move in the -Y axis direction and overlap with the section above point (A). Specifically, the reference lines can be derived as linear relational expressions for points included in the corresponding section (for example, the section below point (A) or the section above point (A)). Therefore, the reference lines may overlap with the profile, and the embodiment in Figure 3 shows the reference lines and the profile separately for the sake of explanation. That is, in the drawings of this application (Figures 3 to 6), the profile and the first reference line L1 and the second reference line L2 are shown separated, but please note that this is for the sake of explanation.

[0068] The control unit 130 sets reference lines according to the rate of change of the resistance value, allowing for the determination of battery resistance abnormalities for each voltage, and enabling a more accurate diagnosis of battery abnormalities.

[0069] In one embodiment, the control unit 130 may set a reference line excluding the target resistance value and target voltage value. The target resistance value and target voltage value may refer to the resistance value and voltage value most recently included in the profile.

[0070] The control unit 130 sets a reference line excluding the target resistance value and target voltage value, allowing for accurate diagnosis of battery abnormalities by comparing the target resistance value with the reference line in real time.

[0071] Here, the baseline may be updated each time the battery's voltage and resistance values ​​are measured. For example, suppose at time n, the nth resistance value is the target resistance value and the nth voltage value is the target voltage value. At time n, the baseline may be set based on the 1st to (n-1)th resistance values ​​and the 1st to (n-1)th voltage values. Then, at time n+1, the (n+1)th resistance value may be determined to be the target resistance value and the (n+1)th voltage value may be determined to be the target voltage value. In this case, the baseline may be updated based on the 1st to (n)th resistance values ​​and the 1st to (n)th voltage values.

[0072] In other words, the battery diagnostic device 100 has the advantage of being able to diagnose the battery condition more accurately by updating the baseline to reflect the latest battery condition information.

[0073] The control unit 130 can set a reference range based on a reference line. This will be explained with reference to Figure 4.

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

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

[0076] Referring to Figure 4, the control unit 130 can set the reference range (B) to be within a predetermined critical value (th) from the reference line L2.

[0077] Here, the critical value (th) is the value added to set the reference range from the baseline. In other words, the critical value (th) is the reference value that determines the normal margin interval for the resistance value. That is, the interval within the critical value (th) from the baseline 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) can be preset to a resistance value of 1Ω or less. Preferably, the critical value (th) can be preset to a resistance value of 0.5Ω or less.

[0079] For example, the critical value (th) can be determined to its optimal value through experiments using batteries under various conditions. Another example is that the critical value (th) may be set considering measurement errors in the voltage value. That is, the measured voltage value may contain measurement errors due to noise. Since voltage measurement errors affect the calculated resistance value, the critical value (th) may be set to account for such voltage measurement errors. In other words, the critical value (th) may be set to prevent misdiagnosis of the battery condition due to voltage measurement errors.

[0080] The control unit 130 can prevent abnormality diagnosis due to slight errors that occur during the process of acquiring the battery's resistance and voltage values ​​by setting the reference range to be within a predetermined critical value from the reference line.

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

[0082] Referring to Figure 4, the reference range is shown based on multiple reference lines represented with reference to a point (A) where the rate of change of the resistance value changes abruptly. The control unit 130 can set the reference range from the first reference line L1 to the critical value (th) in the section where the resistance value is less than or equal to point (A), and can set the reference range from the second reference line L2 to the critical value (th) in the section where the resistance value is greater than or equal to point (A).

[0083] Since the control unit 130 sets a reference range based on different reference lines set with reference to a point (A) where the rate of change of the resistance value changes rapidly, abnormalities in the battery based on its resistance value can be diagnosed more accurately.

[0084] The configuration in which the control unit 130 determines the occurrence of a battery abnormality using a reference range will be explained below with reference to Figure 5.

[0085] Figure 5 is a schematic diagram showing another profile according to one embodiment. Figure 5 shows an XY two-dimensional graph in which the X axis is set to the battery voltage value and the Y axis is set to the battery resistance value.

[0086] In one embodiment, the control unit 130 can diagnose a battery malfunction based on whether the voltage value falls within a voltage range and whether the resistance value corresponding to that voltage value exceeds a reference range.

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

[0088] Referring to Figure 5, the control unit 130 can diagnose whether or not an abnormality has occurred in the battery based on whether or not the resistance value exceeds the reference range, which is section B.

[0089] For example, the control unit 130 may diagnose that there is no abnormality in the battery if the resistance value falls within the reference range. Conversely, the control unit 130 may diagnose that there is an abnormality in the battery if the resistance value exceeds the reference range. Here, the voltage value corresponding to the resistance value may fall within a voltage range.

[0090] Referring to Figure 5, the control unit 130 can diagnose that there is no abnormality in the battery because the first resistance value (R1) belongs to section B, which is within the reference range.

[0091] However, in the case of the second resistance value (R2), it exceeds the reference range, which is section B, so the control unit 130 can diagnose that an abnormality has occurred in the battery.

[0092] The control unit 130 diagnoses abnormalities by comparing the resistance value with a reference range, thereby enabling a non-destructive diagnosis of the battery's condition.

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

[0094] In one embodiment, the profile generation unit 120 can update the profile each time the data acquisition unit 110 acquires resistance and voltage values. For example, each time the data acquisition unit 110 acquires resistance and voltage values, the profile generation unit 120 can update the profile if the acquired voltage value falls within a preset voltage range. The voltage range may be set based on a specific voltage value or based on a resistance reduction rate.

[0095] For example, the voltage interval can be set to an interval in which the rate of decrease in resistance with increasing voltage exceeds a preset critical value. In this case, the profile generation unit 120 can generate a profile if the interval in which the rate of decrease in resistance with increasing voltage exceeds a preset critical value is located within that interval.

[0096] Referring to Figure 6, since the resistance decreases sharply with increasing voltage in the range of 3.5V or less, the profile generation unit 120 can 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 each time the profile is updated. For example, the control unit 130 may set a reference line each time the profile is updated and set a reference range based on the set reference line. The setting of the reference line has been described above, so a further explanation is omitted.

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

[0099] The control unit 130 updates the profile in real time and sets a new reference range based on it, enabling real-time diagnosis of abnormalities due to resistance values.

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

[0101] Figure 7 is a schematic 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 the battery pack 1. That is, the battery pack 1 according to the present invention may include the above-described battery diagnostic device 100, measurement unit 200, charge / discharge unit 300 and one or more battery cells. The battery pack 1 may further include electrical components (relays, fuses, etc.) and a case.

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

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

[0106] The charging / discharging unit 300 can be connected at one end to the positive terminal P+ of the battery pack 1 and at the other end 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 can be electrically connected.

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

[0108] Preferably, each step of the battery diagnostic method can be performed by the battery diagnostic device 100. In the following, content that overlaps with the above description will be omitted or briefly explained.

[0109] The battery information acquisition step S110 is a step in which the resistance value and voltage value of the battery are acquired, and this can be performed by the data acquisition unit 110.

[0110] For example, the data acquisition unit 110 can acquire battery information, such as the voltage and resistance values ​​of the battery, in real time. Depending on the embodiment, the data acquisition unit 110 can acquire battery information that includes resistance and voltage values ​​measured through voltage sensing lines connected to the positive and negative electrodes of the battery. The data acquisition unit 110 can also be connected to a current sensor that measures the battery current. The data acquisition unit 110 can then acquire battery information from the current sensor through the current sensing lines. The data acquisition unit 110 can then acquire the resistance and voltage values ​​of the battery using the information contained in the battery information.

[0111] Depending on the embodiment, the data acquisition unit 110 may be configured to communicate with the outside. The data acquisition unit 110 may receive battery information, including the battery voltage and resistance values, from the outside using communication.

[0112] In one embodiment, the data acquisition unit 110 may acquire the voltage and resistance values ​​at a predetermined time after the battery has finished discharging and has remained in a dormant state. That is, the data acquisition unit 110 can acquire the voltage and resistance values ​​of the battery at a predetermined time after the battery has finished discharging and has remained in a dormant state.

[0113] The profile generation step S120 is a step in which a profile is generated that shows the correspondence between the battery resistance value and voltage value obtained in the battery information acquisition step S110, and this step can be performed by the profile generation unit 120.

[0114] For example, the profile generation unit 120 and the data acquisition unit 110 can be connected to each other via wired and / or wireless connections so that they can communicate with one another. The profile generation unit 120 can then receive battery information, including resistance and voltage values, from the data acquisition unit 110 via a wired and / or wireless communication network.

[0115] The profile generation unit 120 can generate a profile using the battery resistance and voltage values ​​acquired by the data acquisition unit 110. Here, the profile may show the correspondence between the battery resistance and voltage values.

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

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

[0118] For example, the voltage interval can be set to an interval in which the rate of decrease in resistance with increasing voltage exceeds a preset critical value. In this case, the profile generation unit 120 can generate a profile if the interval in which the rate of decrease in resistance with increasing voltage exceeds a preset critical value is located within that interval.

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

[0120] The control unit 130 may set a reference range using the profile received from the profile generation unit 120. The reference range may mean a range in which the rate of change of the battery's resistance value 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 in the profile that shows the rate of change of resistance values ​​with respect to voltage values. For example, in a profile where resistance values ​​with respect to voltage values ​​are displayed, the control unit 130 may set a reference line by approximating a curve that connects each resistance value.

[0122] In one embodiment, multiple reference lines can be set from a single profile according to the rate of change of the resistance value. For example, the control unit 130 can set multiple reference lines in a single 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 be within a predetermined critical value from the reference line. For example, the control unit 130 may estimate a predetermined critical value from the reference line and set the reference range to be within the predetermined critical value.

[0124] The control unit 130 can prevent abnormality diagnosis due to slight errors that occur during the process of acquiring the battery's resistance and voltage values ​​by setting the reference range to be within a predetermined critical value from the reference line.

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

[0126] Since the control unit 130 sets a reference range based on different reference lines set with reference to points where the rate of change of the resistance value changes rapidly, it is possible to more accurately diagnose abnormalities based on the battery's resistance value.

[0127] Battery diagnostic step S140 is a step in which a battery abnormality is diagnosed based on a comparison of the battery's resistance value with a reference range, and can be performed by the control unit 130.

[0128] In one embodiment, the control unit 130 can diagnose a battery malfunction 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 can diagnose that there is no battery malfunction. Conversely, if the resistance value exceeds the reference range, the control unit 130 can diagnose that there is a battery malfunction.

[0129] The control unit 130 diagnoses abnormalities by comparing the resistance value with a reference range, thereby enabling a non-destructive diagnosis of the battery's condition.

[0130] A battery diagnostic device 100 according to one embodiment of the present invention can specifically diagnose battery abnormalities by comparing the battery's resistance value with a reference range.

[0131] A battery diagnostic device 100 according to one 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 from the battery.

[0132] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be embodied through a program that realizes the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such a program is recorded. Such embodiments can be easily realized by those skilled in the art from the description of the embodiments described above.

[0133] As described above, the present invention has been explained with limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within the equivalent scope of the technical concept and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0134] Furthermore, the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention pertains, without departing from the technical spirit of the invention, and is not limited by the embodiments described above and the accompanying drawings. For diverse modifications, all or part of each embodiment may be selectively combined to form the present invention. [Explanation of Symbols]

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

Claims

1. A data acquisition unit configured to acquire the resistance and voltage values ​​of a battery, A profile generation unit configured to generate a profile showing the correspondence between the resistance value and voltage value of the battery acquired by the data acquisition unit, A battery diagnostic device comprising: a control unit configured to set a reference range using a profile received from the profile generation unit, and to 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.

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

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

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

5. The data acquisition unit, The system is configured to acquire the voltage and resistance values ​​at a predetermined time after the battery has finished discharging and has remained in a dormant state. The profile generation unit, The battery diagnostic device according to claim 1, configured to generate the profile if the voltage value falls within a preset voltage range.

6. The aforementioned voltage interval is The battery diagnostic device according to claim 5, wherein the interval in which the rate of decrease in resistance due to the increase in voltage exceeds a preset critical value is set.

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

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

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

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

12. The battery information acquisition stage involves obtaining the battery's resistance and voltage values, A profile generation step generates a profile showing the correspondence between the resistance value and voltage value of the battery obtained in the battery information acquisition step, A reference range setting step in which a reference range is set using the profile generated in the profile generation step, A battery diagnostic method comprising: a battery diagnostic step of diagnosing the occurrence of an abnormality in the battery based on the result of comparing the resistance value of the battery with the reference range.

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