Apparatus and method for diagnosing battery

Abstract

A battery diagnostic apparatus according to an embodiment of the present invention includes: a profile obtaining unit configured to obtain a differential profile indicating a correspondence relationship between a differential capacity and a voltage of a battery; and a control unit configured to determine a target peak in the differential profile, calculate a first capacity and a second capacity of the differential profile on the basis of the target peak, calculate a capacity ratio between the first capacity and the second capacity, and diagnose the state of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0014924, filed on January 31, 2024, the entire contents of which are disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly, to a battery diagnostic device and method for diagnosing the state of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] The present invention has been devised to solve the above problems, and its purpose is to provide a battery diagnosis device and method for diagnosing the state of a battery in a non-destructive manner.

[0007] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0008] A battery diagnosis device according to one aspect of the present invention may include a profile acquisition unit configured to acquire a differential profile indicating a correspondence between a differential capacity and a voltage of a battery; and a control unit configured to determine a target peak in the differential profile, calculate a first capacity and a second capacity of the differential profile based on the target peak, calculate a capacity ratio between the first capacity and the second capacity, and compare the calculated capacity ratio with a pre-stored reference capacity ratio to diagnose a state of the battery.

[0009] The control unit may be configured to determine a peak having the largest differential capacity among a plurality of peaks included in the differential profile as the target peak.

[0010] The control unit may be configured to calculate the first capacity by calculating the capacity of the low-voltage section based on the target peak, and to calculate the second capacity by calculating the capacity of the high-voltage section based on the target peak.

[0011] The control unit may be configured to calculate the capacity ratio by dividing the second capacity by the first capacity.

[0012] The control unit may be configured to diagnose the state of the battery as normal if the difference in capacity ratio between the capacity ratio and the reference capacity ratio is less than or equal to a preset threshold value.

[0013] The control unit may be configured to diagnose the state of the battery as abnormal if the capacity ratio difference exceeds the threshold value.

[0014] The above profile acquisition unit may be configured to acquire a differential profile corresponding to each of a plurality of batteries.

[0015] The control unit may be configured to calculate a capacity ratio of each of the differential profiles for each of the plurality of batteries, compare each of the calculated plurality of capacity ratios with a preset reference capacity ratio for each of the plurality of batteries, and diagnose a relative status between the plurality of batteries based on the comparison result.

[0016] The control unit may be configured to diagnose that the greater the difference in capacity ratio between the capacity ratio and the reference capacity ratio for the plurality of batteries, the higher the degree of degradation.

[0017] A battery pack according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0018] A vehicle according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0019] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a differential profile indicating a correspondence between a differential capacity and a voltage of a battery; a target peak determination step of determining a target peak in the differential profile; a capacity calculation step of calculating a first capacity and a second capacity of the differential profile based on the target peak; a capacity ratio calculation step of calculating a capacity ratio between the first capacity and the second capacity; and a diagnosis step of diagnosing a state of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio.

[0020] According to one aspect of the present invention, a battery diagnostic device has the advantage of being able to non-destructively diagnose the state of a battery based on a capacity ratio obtained from a differential profile of the battery.

[0021] In addition, according to one aspect of the present invention, the battery diagnostic device has an advantage in that it can diagnose the state of the battery based on the overall shape of the differential profile.

[0022] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0023] 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 described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0024] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0025] FIG. 2 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0026] FIG. 3 is a schematic diagram illustrating a plurality of differential profiles according to one embodiment of the present invention.

[0027] FIG. 4 is a diagram schematically illustrating the capacity ratio of a plurality of batteries according to one embodiment of the present invention.

[0028] FIG. 5 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0029] FIG. 6 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0030] FIG. 7 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0031] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0032] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0033] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0034] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0035] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0036] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0037]

[0038] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0039] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0040] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110) and a control unit (120).

[0041] Here, a battery refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may also refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described herein below as referring to a single, independent cell.

[0042] The profile acquisition unit (110) can be configured to acquire a differential profile indicating a correspondence between the differential capacity and voltage of the battery.

[0043] For example, a battery profile is a profile that represents the relationship between voltage (V) and capacity (Q) when the battery's SOC is charged from a preset start SOC or 0% to a preset end SOC or 100%. As another example, a battery profile may represent the relationship between voltage (V) and capacity (Q) when the battery's SOC is discharged from a preset start SOC or 100% to a preset end SOC or 0%.

[0044] And, by differentiating the battery profile with respect to voltage, a differential profile can be generated that represents the correspondence between the differential capacity (dQ / dV) and the voltage (V).

[0045] For example, there are no specific restrictions on the C-rate for charging or discharging to generate a battery profile. However, to obtain more accurate battery profiles and differential profiles, it is desirable to charge or discharge the battery at a low rate. For example, a battery profile can be generated during the process of charging or discharging the battery at 0.05C.

[0046] For example, the profile acquisition unit (110) can directly receive the differential profile of the battery from the outside. That is, the profile acquisition unit (110) can acquire the differential profile by receiving the differential profile through a wired and / or wireless connection to the outside.

[0047] As another example, the profile acquisition unit (110) can directly receive the battery profile of the battery from an external source. Furthermore, the profile acquisition unit (110) can differentiate the battery profile with respect to voltage to generate a differential profile. That is, the profile acquisition unit (110) can be connected to the external source via wires and / or wirelessly to receive the battery profile and directly generate a differential profile from the battery profile, thereby acquiring the differential profile.

[0048] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information, and may generate a differential profile based on the generated battery profile. In other words, the profile acquisition unit (110) may directly generate a differential profile based on the battery information, thereby acquiring the differential profile.

[0049] FIG. 2 is a diagram schematically illustrating a differential profile (P) according to one embodiment of the present invention. For example, the differential profile (P) can be expressed as an XY graph in which the X-axis is set to voltage and the Y-axis is set to differential capacitance.

[0050] The profile acquisition unit (110) may be connected to the control unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the control unit (120) by wire and / or wirelessly. The profile acquisition unit may transmit the acquired differential profile to the control unit (120).

[0051] The control unit (120) may be configured to determine a target peak (tp) in the differential profile (P).

[0052] Specifically, the differential profile (P) may include multiple peaks (p1, p2, p3, p4). Here, the peaks are local maxima of the differential profile (P), which are points where the instantaneous rate of change of the differential capacitance with respect to the voltage is 0. The control unit (120) may determine one of the multiple peaks (p1, p2, p3, p4) included in the differential profile (P) as the target peak (tp) based on the voltage or the differential capacitance.

[0053] Preferably, the control unit (120) may be configured to determine the peak with the largest differential capacity among the plurality of peaks (p1, p2, p3, p4) included in the differential profile (P) as the target peak (tp).

[0054] For example, in the embodiment of FIG. 2, the differential profile (P) may include a first peak (p1), a second peak (p2), a third peak (p3), and a fourth peak (p4). Since the differential capacity of the first peak (p1) is the largest among the first to fourth peaks (p1, p2, p3, p4), the control unit (120) may determine the first peak (p1) as the target peak (tp).

[0055] The control unit (120) can be configured to calculate the first capacity (Q1) and the second capacity (Q2) of the differential profile (P) based on the target peak (tp).

[0056] Specifically, the control unit (120) may be configured to calculate the capacity of the low-voltage section based on the target peak (tp) to produce the first capacity (Q1), and to calculate the capacity of the high-voltage section based on the target peak (tp) to produce the second capacity (Q2).

[0057] For example, the control unit (120) can calculate the capacity from the battery's charging start voltage to the voltage of the target peak (tp) as the first capacity (Q1), and can calculate the capacity from the voltage of the target peak (tp) to the battery's charging end voltage as the second capacity (Q2).

[0058] In the embodiment of FIG. 2, it is assumed that the start voltage of the battery is vi [V], the voltage of the target peak (tp) is vt [V], and the end voltage of the battery is vf [V]. The control unit (120) can calculate the first capacity (Q1) for the voltage range of vi [V] to vt [V]. Specifically, the control unit (120) can calculate the first capacity (Q1) by integrating the differential profile (P) over the voltage in the voltage range of vi [V] to vt [V]. And, the control unit (120) can calculate the second capacity (Q2) for the voltage range of vt [V] to vf [V]. Specifically, the control unit (120) can calculate the second capacity (Q2) by integrating the differential profile (P) over the voltage in the voltage range of vt [V] to vf [V].

[0059] The control unit (120) can be configured to calculate a capacity ratio between the first capacity (Q1) and the second capacity (Q2).

[0060] In general, the state of the positive electrode of the battery is mainly reflected in the high voltage section, and the state of the negative electrode of the battery is mainly reflected in the low voltage section. This is because the negative electrode of the battery includes a negative electrode plateau section in which the voltage change of the negative electrode decreases as the battery capacity increases (i.e., as the battery voltage increases). Accordingly, the control unit (120) can calculate the capacity ratio between the first capacity (Q1) and the second capacity (Q2) in order to diagnose the state of the battery due to the positive electrode.

[0061] Specifically, the control unit (120) can calculate the capacity ratio by calculating the ratio of the second capacity (Q2) to the first capacity (Q1). For example, the control unit (120) can be configured to calculate the capacity ratio by dividing the second capacity (Q2) by the first capacity (Q1). That is, the control unit (120) can calculate the capacity ratio by calculating the formula “first capacity (Q1) ÷ second capacity (Q2).”

[0062] The control unit (120) may be configured to diagnose the condition of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio.

[0063] Here, the reference capacity ratio is a capacity ratio of a reference differential profile, which can be preset to correspond to the battery. For example, the reference capacity ratio may be a capacity ratio of a battery in the beginning of life (BOL) state, a capacity ratio in a previous cycle of the battery, a capacity ratio of a reference battery designed to correspond to the battery, or a theoretically designed capacity ratio.

[0064] The control unit (120) can calculate the capacity ratio difference between the calculated capacity ratio and the preset reference capacity ratio. Furthermore, the control unit (120) can compare the calculated capacity ratio difference with a preset threshold value. Furthermore, the control unit (120) can diagnose the battery's condition based on the comparison results.

[0065] For example, the control unit (120) may be configured to diagnose the battery's status as normal if the difference between the capacity ratio and the reference capacity ratio is below a preset threshold. That is, the control unit (120) may diagnose the battery's status as normal if the difference between the calculated capacity ratio and the reference capacity ratio is below the threshold.

[0066] As another example, the control unit (120) may be configured to diagnose the battery's condition as abnormal if the difference in capacity ratio exceeds a threshold value. That is, the control unit (120) may diagnose the battery's condition as abnormal if the difference between the calculated capacity ratio and the reference capacity ratio exceeds the threshold value.

[0067] Specifically, if the capacity ratio between the first capacity (Q1) and the second capacity (Q2) of the differential profile (P) is significantly changed compared to the reference capacity ratio, the capacity ratio of the differential profile (P) and the reference capacity ratio may differ so as to exceed a threshold value. That is, if the state of the battery is diagnosed as abnormal, it can be said that the shape of the differential profile (P) is significantly changed from the shape of the reference differential profile. Furthermore, since the capacity ratio is a factor indicating the state of the positive electrode, it can be said that the state of the positive electrode of the current battery is significantly deteriorated compared to the state of the positive electrode corresponding to the reference differential profile.

[0068] A battery diagnostic device (100) according to one embodiment of the present invention has the advantage of being able to non-destructively diagnose the state of a battery based on a capacity ratio obtained from a differential profile (P) of the battery.

[0069] In addition, the battery diagnosis device (100) has an advantage in that it can diagnose the state of the battery based on the overall shape of the differential profile (P). That is, the battery diagnosis device (100) can diagnose the state of the battery by considering the overall shape of the differential profile (P), rather than diagnosing the state of the battery solely based on factors related to peaks, such as the number of peaks, differential capacity and voltage, or voltage difference between peaks. Therefore, according to the battery diagnosis device (100), the state of the battery can be diagnosed by considering the overall shape of the differential profile (P), and thus the state of the battery can be diagnosed more accurately than when the state of the battery is diagnosed based on only a specific peak.

[0070]

[0071] Meanwhile, the profile acquisition unit (110) and control unit (120) provided in the battery diagnostic device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the profile acquisition unit (110) and control unit (120) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the profile acquisition unit (110) and control unit (120).

[0072] In addition, the battery diagnostic device (100) may further include a storage unit (130). The storage unit (130) may store data or programs required for each component of the battery diagnostic device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (130) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (130) may store program codes defining processes executable by the profile acquisition unit (110) and the control unit (120).

[0073] For example, the storage unit (130) can store data used to diagnose the status of the battery, such as a differential profile, a reference differential profile, and a reference capacity ratio.

[0074]

[0075] The profile acquisition unit (110) can be configured to acquire a differential profile corresponding to each of a plurality of batteries.

[0076] FIG. 3 is a schematic diagram illustrating a plurality of differential profiles (P1, P2, P3, P4) according to one embodiment of the present invention.

[0077] For example, in the embodiment of FIG. 3, the profile acquisition unit (110) can acquire a first differential profile (P1) of the first battery, a second differential profile (P2) of the second battery, a third differential profile (P3) of the third battery, and a fourth differential profile (P4) of the fourth battery.

[0078] The control unit (120) may be configured to calculate the capacity ratio of each differential profile for each of the plurality of batteries.

[0079] First, the control unit (120) can determine the target peak of each of the plurality of differential profiles (P1, P2, P3, P4). In the embodiment of FIG. 3, the control unit (120) can determine the target peak of the first differential profile (P1) as a peak corresponding to vt1[V], and determine the target peaks of the second to fourth differential profiles (P2, P3, P4) as peaks corresponding to vt2[V].

[0080] Next, the control unit (120) can calculate the capacity ratio of each of the plurality of differential profiles (P1, P2, P3, P4). In the embodiment of FIG. 3, the control unit (120) can calculate the capacity ratio of each of the first differential profile (P1), the second differential profile (P2), the third differential profile (P3), and the fourth differential profile (P4). Specifically, the control unit (120) can calculate the first capacity ratio (q1) of the first differential profile (P1), the second capacity ratio (q2) of the second differential profile (P2), the third capacity ratio (q3) of the third differential profile (P3), and the fourth capacity ratio (q4) of the fourth differential profile (P4).

[0081] The control unit (120) may be configured to compare each of the plurality of calculated capacity ratios with a preset reference capacity ratio for each of the plurality of batteries.

[0082] Specifically, the reference capacity ratio is a capacity ratio determined from a reference differential profile. Since the reference differential profile is independently preset for each battery, the reference capacity ratio can also be preset for each battery. Accordingly, the control unit (120) can compare the corresponding capacity ratio with the reference capacity ratio.

[0083] FIG. 4 is a diagram schematically illustrating the capacity ratio (q) of a plurality of batteries according to one embodiment of the present invention. Specifically, the embodiment of FIG. 4 is a diagram illustrating the reference capacity ratio (r) and the calculated capacity ratio (q) of the first to fourth batteries (B1, B2, B3, and B4).

[0084] For example, in the embodiment of FIG. 4, the control unit (120) can calculate a first capacity ratio (q1) difference between a first reference capacity ratio (r1) of the first battery (B1) and a calculated first capacity ratio (q1). In addition, the control unit (120) can calculate a second capacity ratio (q2) difference between a second reference capacity ratio (r2) of the second battery (B2) and a calculated second capacity ratio (q2). In addition, the control unit (120) can calculate a third capacity ratio (q3) difference between a third reference capacity ratio (r3) of the third battery (B3) and a calculated third capacity ratio (q3). In addition, the control unit (120) can calculate a fourth capacity ratio (q4) difference between a fourth reference capacity ratio (r4) of the fourth battery (B4) and a calculated fourth capacity ratio (q4).

[0085] The control unit (120) may be configured to diagnose the relative status between multiple batteries (B1, B2, B3, B4) based on the comparison results.

[0086] Specifically, the control unit (120) can directly compare the magnitude of the differences in the calculated capacity ratios. In addition, the control unit (120) can be configured to diagnose that the greater the difference in capacity ratio between the capacity ratio and the reference capacity ratio for the plurality of batteries (B1, B2, B3, B4), the higher the degree of degradation.

[0087] For example, in the embodiment of Fig. 4, when comparing the magnitude of the differences in the first to fourth capacity ratios (q1, q2, q3, q4), the magnitude of the calculated capacity ratio differences is in the order of the fourth capacity ratio (q4) difference, the first capacity ratio (q1) difference, the second capacity ratio (q2) difference, and the third capacity ratio (q3) difference. That is, the fourth capacity ratio (q4) difference is the largest, the third capacity ratio (q3) difference is the smallest, and the first capacity ratio (q1) difference is larger than the second capacity ratio (q2) difference.

[0088] Accordingly, the control unit (120) can diagnose that the fourth battery (B4), the first battery (B1), the second battery (B2), and the third battery (B3) have the highest deterioration levels in that order. That is, the control unit (120) can diagnose that the fourth battery (B4) is the most deteriorated and the third battery (B3) is the least deteriorated. In addition, the control unit (120) can diagnose that the first battery (B1) is more deteriorated than the second battery (B2).

[0089] A battery diagnostic device (100) according to one embodiment of the present invention has the advantage of being able to diagnose the relative degradation degree between multiple batteries based on differential profiles of the multiple batteries.

[0090]

[0091] The battery diagnosis device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery diagnosis device (100) described above. In this configuration, at least some of the components of the battery diagnosis device (100) can be implemented by supplementing or adding to the functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), the control unit (120), and the storage unit (130) of the battery diagnosis device (100) can be implemented as components of the BMS.

[0092] In addition, the battery diagnostic device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0093] FIG. 5 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0094] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0095] The measuring unit (12) can be connected to a first sensing line (SL1), a second sensing line (SL2), and a third sensing line (SL3). Specifically, the measuring unit (12) can be connected to a positive terminal of the battery (11) through the first sensing line (SL1), and can be connected to a negative terminal of the battery (11) through the second sensing line (SL2). The measuring unit (12) can measure the voltage of the battery (11) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0096] And, the measuring unit (12) can be connected to the current measuring unit (A) through the third sensing line (SL3). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (11). The measuring unit (12) can measure the charging current of the battery (11) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (12) can measure the discharging current of the battery (11) through the third sensing line (SL3) to calculate the discharging amount.

[0097] For example, the profile acquisition unit (110) can receive battery information about the voltage and current of the battery from the measurement unit (12). Then, the profile acquisition unit (110) can generate a battery profile and a differential profile based on the battery information.

[0098] As another example, the profile acquisition unit (110) can receive a battery profile from the measurement unit (12). Then, the profile acquisition unit (110) can generate a differential profile based on the battery profile.

[0099] As another example, the profile acquisition unit (110) can receive a differential profile from the measurement unit (12).

[0100] An external device can be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (10). For example, the external device can be a charging device or a load. In addition, the positive terminal of the battery (11), the positive terminal (P+) of the battery pack (10), the external device, the negative terminal (P-) of the battery pack (10), and the negative terminal of the battery (11) can be electrically connected.

[0101]

[0102] FIG. 6 is a schematic drawing of a vehicle (600) according to another embodiment of the present invention.

[0103] Referring to FIG. 6, a battery pack (610) according to an embodiment of the present invention may be included in a vehicle (600), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (610) may drive the vehicle (600) by supplying power to a motor through an inverter provided in the vehicle (600). Here, the battery pack (610) may include a battery diagnostic device (100). That is, the vehicle (600) may include a battery diagnostic device (100). In this case, the battery diagnostic device (100) may be an onboard device included in the vehicle (600).

[0104]

[0105] FIG. 7 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0106] Referring to FIG. 7, the battery diagnosis method may include a profile acquisition step (S100), a target peak determination step (S200), a capacity calculation step (S300), a capacity ratio calculation step (S400), and a diagnosis step (S500).

[0107] Preferably, each step of the battery diagnosis method can be performed by a battery diagnosis device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.

[0108] The profile acquisition step (S100) is a step of acquiring a differential profile indicating a correspondence between the differential capacity and voltage of the battery, and can be performed by the profile acquisition unit (110).

[0109] For example, the profile acquisition unit (110) can directly receive the differential profile of the battery from the outside. That is, the profile acquisition unit (110) can acquire the differential profile by receiving the differential profile through a wired and / or wireless connection to the outside.

[0110] As another example, the profile acquisition unit (110) can directly receive the battery profile of the battery from an external source. Furthermore, the profile acquisition unit (110) can differentiate the battery profile with respect to voltage to generate a differential profile. That is, the profile acquisition unit (110) can be connected to the external source via wires and / or wirelessly to receive the battery profile and directly generate a differential profile from the battery profile, thereby acquiring the differential profile.

[0111] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information, and may generate a differential profile based on the generated battery profile. In other words, the profile acquisition unit (110) may directly generate a differential profile based on the battery information, thereby acquiring the differential profile.

[0112] The target peak determination step (S200) is a step of determining a target peak (tp) in a differential profile, and can be performed by the control unit (120).

[0113] For example, in the embodiment of FIG. 2, the control unit (120) may be configured to determine the first peak (p1) having the largest differential capacity among the plurality of peaks (p1, p2, p3, p4) included in the differential profile (P) as the target peak (tp).

[0114] The capacity calculation step (S300) is a step of calculating the first capacity (Q1) and the second capacity (Q2) of the differential profile (P) based on the target peak (tp), and can be performed by the control unit (120).

[0115] For example, the control unit (120) may be configured to calculate the capacity of a low-voltage section based on a target peak (tp) to produce a first capacity (Q1), and to calculate the capacity of a high-voltage section based on a target peak (tp) to produce a second capacity (Q2).

[0116] The capacity ratio calculation step (S400) is a step of calculating the capacity ratio between the first capacity (Q1) and the second capacity (Q2), and can be performed by the control unit (120).

[0117] Specifically, the control unit (120) can calculate the capacity ratio by calculating the ratio of the second capacity (Q2) to the first capacity (Q1). For example, the control unit (120) can be configured to calculate the capacity ratio by dividing the second capacity (Q2) by the first capacity (Q1).

[0118] The diagnosis step (S500) is a step for diagnosing the state of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio, and can be performed by the control unit (120).

[0119] For example, the control unit (120) may be configured to diagnose the state of the battery as normal if the difference in capacity ratio between the capacity ratio and the reference capacity ratio is less than a preset threshold value.

[0120] As another example, the control unit (120) may be configured to diagnose the state of the battery as abnormal if the capacity ratio difference exceeds a threshold value.

[0121]

[0122] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function 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 an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0123] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0124] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0125]

[0126] (Explanation of symbols)

[0127] 10: Battery pack

[0128] 11: Battery

[0129] 12: Measurement section

[0130] 100: Battery Diagnostic Device

[0131] 110: Profile acquisition section

[0132] 120: Control unit

[0133] 130: Storage

[0134] 600: Car

[0135] 610: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a differential profile indicating a correspondence between the differential capacity and voltage of the battery; and A battery diagnosis device characterized by comprising a control unit configured to determine a target peak in the differential profile, calculate a first capacity and a second capacity of the differential profile based on the target peak, calculate a capacity ratio between the first capacity and the second capacity, and diagnose the state of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio.

2. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to determine the peak having the largest differential capacity among the plurality of peaks included in the differential profile as the target peak.

3. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the first capacity by calculating the capacity of the low voltage section based on the target peak, and to calculate the second capacity by calculating the capacity of the high voltage section based on the target peak.

4. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the capacity ratio by dividing the second capacity by the first capacity.

5. In paragraph 1, The above control unit, If the capacity ratio difference between the above capacity ratio and the above reference capacity ratio is less than or equal to a preset threshold, the state of the battery is diagnosed as normal, A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as abnormal when the capacity ratio difference exceeds the threshold value.

6. In paragraph 1, The above profile acquisition unit, It is configured to obtain a differential profile corresponding to each of the plurality of batteries, The above control unit, A battery diagnosis device characterized in that it is configured to calculate the capacity ratio of each of the differential profiles for each of the plurality of batteries, compare each of the calculated plurality of capacity ratios with a preset reference capacity ratio for each of the plurality of batteries, and diagnose the relative status between the plurality of batteries based on the comparison result.

7. In paragraph 6, The above control unit, A battery diagnosis device characterized in that it is configured to diagnose that the greater the difference in capacity ratio between the capacity ratio and the reference capacity ratio for the plurality of batteries, the higher the degree of degradation.

8. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 7.

9. A vehicle including a battery diagnostic device according to any one of paragraphs 1 to 7.

10. A profile acquisition step for acquiring a differential profile representing the correspondence between the differential capacity and voltage of the battery; A target peak determination step for determining a target peak in the above differential profile; A capacity calculation step for calculating the first capacity and the second capacity of the differential profile based on the target peak; A capacity ratio calculation step for calculating a capacity ratio between the first capacity and the second capacity; and A battery diagnosis method characterized by including a diagnosis step of diagnosing the state of the battery by comparing the calculated capacity ratio with a pre-stored reference capacity ratio.

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