Apparatus and method for diagnosing battery

Abstract

An apparatus for diagnosing a battery, according to one embodiment of the present invention, comprises: a profile acquisition unit for acquiring a first differential profile based on a battery differential voltage and capacity that correspond to a charging process, and a second differential profile based on the battery differential voltage and capacity that correspond to a discharging process; and a control unit for calculating the number of charging peaks included in a first capacity section in the first differential profile, calculating the number of discharging peaks included in a second capacity section in the second differential profile, and diagnosing the state of the battery according to the number of charging peaks and the number of discharging peaks.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2023-0172711, filed on December 1, 2023, 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 diagnosis device and method, and more particularly, to a battery diagnosis device and method for diagnosing the state of a battery based on the number of peaks.

[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 based on the number of peaks.

[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 first differential profile based on a differential voltage and capacity of a battery corresponding to a charging process and a second differential profile based on the differential voltage and capacity of the battery corresponding to a discharging process; and a control unit configured to calculate the number of charging peaks included in a first capacity section from the first differential profile, calculate the number of discharging peaks included in a second capacity section from the second differential profile, and diagnose a state of the battery based on the number of charging peaks and the number of discharging peaks.

[0009] The control unit may be configured to compare the sum of the charge peaks and the discharge peaks with a preset reference number and diagnose the state of the battery based on the comparison result.

[0010] The control unit may be configured to diagnose the state of the battery as a BOL state, a MOL state, or an EOL state based on the comparison result.

[0011] The control unit may be configured to diagnose the state of the battery as a BOL state if the total number is greater than or equal to a preset first reference number.

[0012] The control unit may be configured to diagnose the state of the battery as a MOL state when the summed number is less than the first reference number and exceeds a preset second reference number.

[0013] The control unit may be configured to diagnose the state of the battery as the MOL state or EOL state if the summed number is equal to the second reference number.

[0014] The control unit may be configured to calculate the capacity of the battery when the summed number is equal to the second reference number, compare the calculated capacity with a preset reference capacity, and diagnose the state of the battery as the MOL state or EOL state based on the comparison result.

[0015] The above control unit may be configured to calculate a ratio of the calculated capacity to the reference capacity.

[0016] The control unit may be configured to diagnose the state of the battery as the MOL state if the calculated ratio is greater than or equal to a preset reference ratio.

[0017] The control unit may be configured to diagnose the state of the battery as the EOL state if the calculated ratio is less than the reference ratio.

[0018] The control unit may be configured to calculate the capacity of the battery based on the second differential profile.

[0019] The control unit may be configured to determine a first capacity corresponding to the lowest differential voltage in the first differential profile, and set a capacity section below the determined first capacity as the first capacity section.

[0020] The control unit may be configured to determine a second capacity corresponding to the highest differential voltage in the second differential profile, and set a capacity section equal to or greater than the determined second capacity as the second capacity section.

[0021] The control unit may be configured to divide the entire capacity section of the battery into a lower capacity section and an upper capacity section, determine the first capacity in the lower capacity section of the first differential profile, and determine the second capacity in the upper capacity section of the second differential profile.

[0022] 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.

[0023] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a first differential profile based on a differential voltage and capacity of a battery corresponding to a charging process and a second differential profile based on the differential voltage and capacity of the battery corresponding to a discharging process; a peak count calculation step of calculating the number of charging peaks included in a first capacity section from the first differential profile and calculating the number of discharging peaks included in a second capacity section from the second differential profile; and a battery diagnosis step of diagnosing a state of the battery based on the number of charging peaks and the number of discharging peaks.

[0024] According to one aspect of the present invention, there is an advantage in that the condition of the battery can be diagnosed even without additional measurement or inspection to diagnose the condition of the battery.

[0025] In addition, according to one aspect of the present invention, since the state of the battery is diagnosed based on the number of charge / discharge peaks, there is an advantage in that the state of the battery can be diagnosed in a non-destructive manner.

[0026] 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.

[0027] 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.

[0028] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0029] FIG. 2 is a schematic diagram illustrating a first differential profile of a battery according to one embodiment of the present invention.

[0030] FIG. 3 is a schematic diagram illustrating a second differential profile of a battery according to one embodiment of the present invention.

[0031] FIG. 4 is a schematic diagram illustrating a diagnostic embodiment of multiple batteries according to one embodiment of the present invention.

[0032] FIG. 5 is a schematic diagram illustrating a first differential profile of another battery according to one embodiment of the present invention.

[0033] FIG. 6 is a schematic diagram illustrating a second differential profile of another battery according to one embodiment of the present invention.

[0034] FIG. 7 is a drawing illustrating an exemplary configuration of a battery pack including a battery diagnostic device according to one embodiment of the present invention.

[0035] FIG. 8 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0036] 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 spirit 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 possible manner.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042]

[0043] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0044] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0045] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110), a control unit (120), and a storage unit (130).

[0046] 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.

[0047] The profile acquisition unit (110) can be configured to acquire a first differential profile (D1) based on the differential voltage and capacity of the battery corresponding to the charging process and a second differential profile (D2) based on the differential voltage and capacity of the battery corresponding to the discharging process.

[0048] Specifically, the battery profile is a profile that represents the correspondence between the voltage (V) and capacity (Q) of the battery. For example, the battery profile can be expressed as a two-dimensional graph in which the X-axis is set to capacity and the Y-axis is set to voltage. Then, when the battery profile is differentiated with respect to capacity, a differential profile that represents the correspondence between the differential voltage (dV / dQ) and capacity (Q) can be generated. Here, the differential voltage (dV / dQ) is a value obtained by differentiating the voltage (V) with respect to the capacity (Q), and can represent the instantaneous rate of change of the voltage with respect to the capacity.

[0049] Here, 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 by charging or discharging the battery at 0.05C.

[0050] The first differential profile (D1) is a profile obtained by differentiating the battery profile generated during the charging process with respect to capacity. Furthermore, the second differential profile (D2) is a profile obtained by differentiating the battery profile generated during the discharging process with respect to capacity.

[0051] Fig. 2 is a schematic diagram illustrating a first differential profile (D1) of a battery according to an embodiment of the present invention. Fig. 3 is a schematic diagram illustrating a second differential profile (D2) of a battery according to an embodiment of the present invention. In the embodiments of Figs. 2 and 3, when the sign of the charge direction is set to plus (+) and the sign of the discharge direction is set to minus (-), the differential voltage of the first differential profile (D1) is expressed as a positive number, and the differential voltage of the second differential profile (D2) is expressed as a negative number.

[0052] For example, the profile acquisition unit (110) can directly receive the first and second differential profiles (D1, D2) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the first and second differential profiles (D1, D2) by being connected to the outside via wire and / or wirelessly and receiving the first and second differential profiles (D1, D2).

[0053] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Here, the battery information may be divided into information corresponding to a charging process and information corresponding to a discharging process. In addition, the profile acquisition unit (110) may generate a first battery (B1) profile corresponding to a charging process and a second battery (B2) profile corresponding to a discharging process based on the received battery information. The profile acquisition unit (110) may generate a first differential profile (D1) based on the first battery (B1) profile, and may generate a second differential profile (D2) based on the second battery (B2) profile. That is, the profile acquisition unit (110) may directly generate the first and second differential profiles (D1, D2) based on the battery information, thereby acquiring the first and second differential profiles (D1, D2).

[0054] 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 first and second differential profiles (D1, D2) to the control unit (120).

[0055] The control unit (120) may be configured to calculate the number of charging peaks included in the first capacity section (R1) in the first differential profile (D1).

[0056] Specifically, the first differential profile (D1) may include a plurality of charging peaks. Here, the charging peak refers to a point having an upward convex shape among points where the instantaneous rate of change of the differential voltage with respect to the capacity is 0. That is, the instantaneous rate of change of the differential voltage with respect to the capacity on the low-capacity side based on the charging peak is positive, and the instantaneous rate of change of the differential voltage with respect to the capacity on the high-capacity side is negative. The control unit (120) may calculate the number of charging peaks included in the first capacity section (R1) among the plurality of charging peaks included in the first differential profile (D1).

[0057] For example, in the embodiment of FIG. 2, the first differential profile (D1) includes first to fifth charging peaks (pc1, pc2, pc3, pc4, pc5). In addition, the first capacity section (R1) set for the first differential profile (D1) includes first to third charging peaks (pc1, pc2, pc3). Accordingly, the control unit (120) can calculate the number of charging peaks included in the first capacity section (R1) of the first differential profile (D1) as three.

[0058] The control unit (120) may be configured to calculate the number of discharge peaks included in the second capacity section (R2) in the second differential profile (D2).

[0059] Specifically, the second differential profile (D2) may include a plurality of discharge peaks. Here, the discharge peak refers to a point having a downward convex shape among the points where the instantaneous rate of change of the differential voltage with respect to the capacity is 0. That is, the instantaneous rate of change of the differential voltage with respect to the capacity on the low-capacity side based on the discharge peak is negative, and the instantaneous rate of change of the differential voltage with respect to the capacity on the high-capacity side is positive. The control unit (120) may calculate the number of discharge peaks included in the second capacity section (R2) among the plurality of discharge peaks included in the second differential profile (D2).

[0060] For example, in the embodiment of FIG. 3, the second differential profile (D2) includes first to third discharge peaks (pd1, pd2, pd3). In addition, the second capacity section (R2) set for the second differential profile (D2) includes second and third discharge peaks (pd2, pd3). Therefore, the control unit (120) can calculate the number of discharge peaks included in the second capacity section (R2) of the second differential profile (D2) as two.

[0061] The control unit (120) may be configured to diagnose the state of the battery based on the number of charging peaks and discharging peaks.

[0062] Specifically, the control unit (120) may be configured to compare the sum of the number of charging peaks and discharging peaks with a preset reference number.

[0063] Here, the reference number may be a preset value corresponding to the state of the battery.

[0064] For example, in the embodiments of FIGS. 2 and 3, the number of charging peaks is three, and the number of discharging peaks is two. The control unit (120) can compare the sum of the charging peaks and the discharging peaks (five) with a preset reference number. Specifically, the control unit (120) can compare the magnitude of the sum (five) with the reference number.

[0065] The control unit (120) may be configured to diagnose the status of the battery based on the comparison result.

[0066] Specifically, the control unit (120) may be configured to diagnose the state of the battery as a BOL (Beginning of life) state, MOL (Middle of life) state, or EOL (End of life) state.

[0067] The BOL state refers to the initial state of the battery. The state of a battery that has completed a predetermined number of charge / discharge cycles may correspond to the BOL state. In one embodiment, the state of a battery that has completed approximately 10 charge / discharge cycles may correspond to the BOL state.

[0068] MOL status refers to the state in which the battery has deteriorated over time. In other words, MOL status is a state in which no problems are expected to occur even if the battery continues to be used.

[0069] End-of-Life (EOL) status refers to a condition in which a battery has deteriorated significantly and is recommended for discontinuation. For example, a battery with a state of health (SOH) of less than 80% is considered EOL. Continued use of a battery in EOL status can lead to unexpected problems, such as sudden death or venting, so battery use is recommended.

[0070] That is, the battery diagnosis device (100) can diagnose the state of the battery as a BOL state, MOL state, or EOL state using a relatively simple method of comparing the sum of the number of charging and discharging peaks with the size of the reference number. That is, according to the battery diagnosis device (100), there is an advantage in that the state of the battery can be diagnosed even without additional measurement or inspection to diagnose the state of the battery. In addition, according to the battery diagnosis device (100), since the state of the battery is diagnosed based on the number of charging and discharging peaks, there is an advantage in that the state of the battery can be diagnosed in a non-destructive manner.

[0071]

[0072] Meanwhile, the profile acquisition unit (110) and the 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 the 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 the control unit (120). The memory may be located inside or outside the profile acquisition unit (110) and / or the control unit (120), and may be connected to the profile acquisition unit (110) and the control unit (120) by various well-known means.

[0073] 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).

[0074]

[0075] A plurality of reference numbers can be preset. Then, the control unit (120) can compare the sum of the numbers with the plurality of reference numbers and diagnose the battery status based on the comparison result.

[0076] Here, the battery status can be distinguished by each of a plurality of criteria. Therefore, preferably, the preset criteria number may be smaller than the number of battery statuses being diagnosed. For example, if there are three battery statuses being diagnosed, the preset criteria number may be two. In other words, a first criteria number and a second criteria number may be preset.

[0077] And, the first capacity section (R1) of the first differential profile (D1) may include at least one charging peak, and the second capacity section (R2) of the second differential profile (D2) may include at least one discharging peak. Accordingly, the minimum value of the summation number may be 2. That is, any one of the plurality of reference numbers may be set so as to distinguish the state of the battery corresponding to the minimum value of the summation number.

[0078] Hereinafter, it is assumed that the first reference number is set to 4 and the second reference number is set to 2. In addition, it is explained that the control unit (120) diagnoses the battery status as a BOL status, MOL status, or EOL status based on the result of comparing the sum number with the first reference number and the second reference number. Here, it can be said that the second reference number is preset to distinguish the battery status corresponding to the minimum value of the sum number.

[0079] For example, if the sum total is greater than or equal to a first preset reference number, the control unit (120) can diagnose the battery's status as a BOL state. As another example, if the sum total is less than the first reference number and exceeds a second preset reference number, the control unit (120) can diagnose the battery's status as a MOL state. As another example, if the sum total is equal to the second reference number, the control unit (120) can diagnose the battery's status as a MOL state or an EOL state.

[0080] FIG. 4 is a schematic diagram illustrating a diagnostic embodiment of multiple batteries according to one embodiment of the present invention.

[0081] Specifically, the first battery (B1) has three charging peaks, two discharge peaks, and a total of five. The second battery (B2) has three charging peaks, one discharge peak, and a total of four. The third battery (B3) has two charging peaks, two discharge peaks, and a total of four. The fourth battery (B4) has two charging peaks, one discharge peak, and a total of three. The fifth battery (B5) has one charging peak, two discharge peaks, and a total of three. The sixth battery (B6) has one charging peak, one discharge peak, and a total of two.

[0082] The total number of the first battery (B1) is 5, which is greater than or equal to the first reference number (4). Therefore, the control unit (120) can diagnose the state of the first battery (B1) as a BOL state.

[0083] The combined number of the second battery (B2) and the third battery (B3) is 4, which is greater than or equal to the first reference number (4). Therefore, the control unit (120) can diagnose the status of the second battery (B2) and the third battery (B3) as a BOL status.

[0084] The combined number of the fourth battery (B4) and the fifth battery (B5) is three, which is less than the first reference number (four) and exceeds the second reference number (two). Therefore, the control unit (120) can diagnose the status of the fourth battery (B4) and the fifth battery (B5) as MOL.

[0085] The total number of batteries (B6) is 2, which is the same as the second reference number (2). Therefore, the control unit (120) can diagnose the state of the sixth battery (B6) as MOL or EOL. In other words, when the total number of batteries is 2, the state of the battery cannot be accurately distinguished based on the number of charging peaks and discharging peaks alone. In this case, the control unit (120) can diagnose the state of the battery as MOL or EOL by further considering the capacity of the battery.

[0086]

[0087] The control unit (120) may be configured to calculate the capacity of the battery if the summed number is equal to the second reference number.

[0088] Fig. 5 is a schematic diagram illustrating a first differential profile (D1) of another battery according to an embodiment of the present invention. Fig. 6 is a schematic diagram illustrating a second differential profile (D2) of another battery according to an embodiment of the present invention. In the embodiments of Figs. 5 and 6, when the sign of the charge direction is set to plus (+) and the sign of the discharge direction is set to minus (-), the differential voltage of the first differential profile (D1) is expressed as a positive number, and the differential voltage of the second differential profile (D2) is expressed as a negative number.

[0089] In the embodiment of FIG. 5, the first differential profile (D1) includes the first to third charging peaks (pc1, pc2, pc3), but the first capacity section (R1) includes only the first charging peak (pc1). That is, the number of charging peaks is 1.

[0090] In the embodiment of FIG. 6, the second differential profile (D2) includes a first discharge peak (pd1) and a second discharge peak (pd2), but the second capacity section (R2) includes only the second discharge peak (pd2). That is, the number of discharge peaks is 1.

[0091] In the embodiments of FIGS. 5 and 6, since the sum of the number of charging peaks and discharging peaks is equal to the second reference number (2), the control unit (120) can calculate the capacity of the battery in order to specifically diagnose the state of the battery.

[0092] Specifically, the control unit (120) can calculate the capacity of the battery based on the first differential profile (D1) and / or the second differential profile (D2).

[0093] For example, in the embodiment of FIG. 5, the battery's charge start capacity is Qci and the charge end capacity is Qcf in the first differential profile (D1). The control unit (120) can calculate the battery capacity based on the difference (Qcf-Qci) between the charge end capacity and the charge start capacity.

[0094] As another example, in the embodiment of FIG. 6, in the second differential profile (D2), the discharge start capacity of the battery is Qdci, and the discharge end capacity is Qdcf. The control unit (120) can calculate the capacity of the battery based on the difference (Qdci-Qdcf) between the discharge start capacity and the discharge end capacity.

[0095] As another example, the control unit (120) may calculate the capacity of the battery by calculating the median value of the capacity calculated based on the first differential profile (D1) and the capacity calculated based on the second differential profile (D2).

[0096] The control unit (120) can be configured to compare the calculated capacity with a preset reference capacity.

[0097] Specifically, the control unit (120) may be configured to calculate a ratio of the calculated capacity to a reference capacity. Here, the reference capacity may be preset as the initial capacity of the battery. For example, the reference capacity may be preset as the design capacity of the battery.

[0098] The control unit (120) can calculate the ratio of the calculated capacity to the reference capacity by calculating the formula "calculated capacity ÷ reference capacity." In this case, the calculation result can be included in the range of 0 or more and 1 or less. In addition, the control unit (120) can also calculate the ratio of the calculated capacity to the reference capacity as a percentage. That is, the control unit (120) can estimate the SOH of the battery based on the calculated capacity and the reference capacity.

[0099] In addition, the control unit (120) can be configured to diagnose the state of the battery as a MOL state or an EOL state based on the comparison result.

[0100] Specifically, the control unit (120) can compare the comparison result (the ratio of the calculated capacity to the reference capacity) with a preset reference ratio. Here, the reference ratio can be preset as a value that can distinguish the battery status between a MOL state and an EOL state. For example, the reference ratio can be preset to 80%.

[0101] For example, if the calculated ratio is greater than or equal to a preset reference ratio, the control unit (120) can diagnose the battery's status as a MOL state. As another example, if the calculated ratio is less than the reference ratio, the control unit (120) can diagnose the battery's status as an EOL state.

[0102] The battery diagnostic device (100) can primarily diagnose the condition of a battery based on the number of peaks, and secondarily diagnose the condition of a battery based on the capacity of the battery. In other words, the condition of the battery can be specifically diagnosed by considering the number of peaks and the capacity.

[0103]

[0104] Preferably, the control unit (120) may be configured to calculate the battery capacity based on the second differential profile (D2). Ideally, the battery's charge and discharge capacities are identical, but differences in charge and discharge capacities may occur depending on the battery's electrochemical characteristics. This phenomenon is called hysteresis.

[0105] In judging the life performance of a battery, the discharge performance (i.e., discharge capacity), which is how much energy the battery can release, may be considered a more important factor than the charge performance (i.e., charge capacity), which is how much energy the battery can store.

[0106] Accordingly, if the control unit (120) cannot diagnose the state of the battery with only the sum of the number of charge peaks and discharge peaks, it can diagnose the state of the battery more specifically by considering the discharge capacity of the battery based on the second differential profile (D2).

[0107]

[0108] Below, an embodiment of setting a first capacity section (R1) and a second capacity section (R2) is specifically described.

[0109] The control unit (120) may be configured to determine the first capacitance (Q1) corresponding to the lowest differential voltage in the first differential profile (D1).

[0110] For example, in the embodiment of FIG. 2, the lowest differential voltage of the first differential profile (D1) is dV1. The control unit (120) can determine the first capacitance (Q1) corresponding to the lowest differential voltage dV1 as Q1.

[0111] In addition, the control unit (120) can be configured to set a capacity section below the determined first capacity (Q1) as the first capacity section (R1).

[0112] For example, in the embodiment of FIG. 2, the control unit (120) can set the Qci to Q1 section as the first capacity section (R1). Then, the control unit (120) can calculate the number of charging peaks included in the first capacity section (R1).

[0113] The control unit (120) may be configured to determine the second capacitance (Q2) corresponding to the highest differential voltage in the second differential profile (D2).

[0114] For example, in the embodiment of FIG. 3, the highest differential voltage of the second differential profile (D2) is dV2. The control unit (120) can determine the second capacitance (Q2) corresponding to the highest differential voltage dV2 as Q2.

[0115] The control unit (120) can be configured to set a capacity section greater than or equal to the determined second capacity (Q2) as the second capacity section (R2).

[0116] For example, in the embodiment of FIG. 3, the control unit (120) can set the Q2 to Qdci section as the second capacity section (R2). In addition, the control unit (120) can calculate the number of discharge peaks included in the second capacity section (R2).

[0117] Specifically, the charging peak of the first differential profile (D1) is a peak with an upward convex shape. Furthermore, the point corresponding to the lowest differential voltage is a point with a downward convex shape. In other words, the charging peak used to diagnose the battery condition is located on the low-capacity side, from the point corresponding to the lowest differential voltage.

[0118] Additionally, the discharge peak of the second differential profile (D2) is a downward convex peak. Furthermore, the point corresponding to the highest differential voltage is also an upward convex point. In other words, the discharge peak used to diagnose the battery's condition is included in the high-capacity range from the point corresponding to the highest differential voltage.

[0119] Accordingly, the control unit (120) can calculate the number of charging peaks by considering only the first capacity section (R1) of the first differential profile (D1), and can calculate the number of discharging peaks by considering only the second capacity section (R2) of the second differential profile (D2).

[0120] That is, since a process of separately selecting charging peaks and discharging peaks after calculating all peaks in the entire capacity range is not required, the battery diagnosis device (100) has the advantage of being able to diagnose the state of the battery more quickly and saving system resources consumed in diagnosing the state of the battery.

[0121]

[0122] Meanwhile, the control unit (120) may be configured to divide the entire capacity section of the battery into a lower capacity section and an upper capacity section.

[0123] For example, in the embodiment of FIG. 2, the entire capacity section is a Qci to Qcf section. The control unit (120) can divide the entire capacity section into two, dividing the lower capacity section into a Qci to (Qcf-Qci)÷2 section, and the upper capacity section into a (Qcf-Qci)÷2 to Qcf section.

[0124] As another example, in the embodiment of FIG. 3, the entire capacity section is a Qdcf to Qdci section. The control unit (120) can divide the entire capacity section into two, dividing the lower capacity section into a Qdcf to (Qdci-Qdcf)÷2 section, and the upper capacity section into a (Qdci-Qdcf)÷2 to Qdci section.

[0125] The control unit (120) may be configured to determine the first capacity (Q1) in the lower capacity section of the first differential profile (D1) and to determine the second capacity (Q2) in the upper capacity section of the second differential profile (D2).

[0126] In general, the point corresponding to the lowest differential voltage in the first differential profile (D1) is included in the lower capacity section, and the point corresponding to the highest differential voltage in the second differential profile (D2) is included in the upper capacity section. Therefore, the control unit (120) can determine the first capacity (Q1) in the lower capacity section of the first differential profile (D1) and the second capacity (Q2) in the upper capacity section of the second differential profile (D2), thereby determining the first capacity (Q1) and the second capacity (Q2) more quickly.

[0127]

[0128] 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.

[0129]

[0130] In addition, the battery diagnostic device (100) according to the present invention may be installed 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.

[0131] FIG. 7 is a drawing illustrating an exemplary configuration of a battery pack including a battery diagnostic device (100) according to one embodiment of the present invention.

[0132] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (1), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (1).

[0133] 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).

[0134] 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.

[0135] The load (2) can have one end connected to the positive terminal (P+) of the battery pack (1) and the other end connected to the negative terminal (P-) of the battery pack (1). Accordingly, the positive terminal of the battery (11), the positive terminal (P+) of the battery pack (1), the load (2), the negative terminal (P-) of the battery pack (1), and the negative terminal of the battery (11) can be electrically connected.

[0136]

[0137] FIG. 8 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0138] Referring to FIG. 8, the battery diagnosis method may include a profile acquisition step (S100), a peak count calculation step (S200), and a battery diagnosis step (S300).

[0139] 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.

[0140] The profile acquisition step (S100) is a step of acquiring a first differential profile (D1) based on the differential voltage and capacity of the battery corresponding to the charging process and a second differential profile (D2) based on the differential voltage and capacity of the battery corresponding to the discharging process, and can be performed by the profile acquisition unit (110).

[0141] For example, the profile acquisition unit (110) can directly receive the first and second differential profiles (D1, D2) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the first and second differential profiles (D1, D2) by being connected to the outside via wire and / or wirelessly and receiving the first and second differential profiles (D1, D2).

[0142] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Here, the battery information may be divided into information corresponding to the charging process and information corresponding to the discharging process. Furthermore, the profile acquisition unit (110) may directly generate the first and second differential profiles (D1, D2) based on the battery information, thereby acquiring the first and second differential profiles (D1, D2).

[0143] The peak count calculation step (S200) is a step of calculating the number of charging peaks included in the first capacity section (R1) in the first differential profile (D1) and calculating the number of discharging peaks included in the second capacity section (R2) in the second differential profile (D2), and can be performed by the control unit (120).

[0144] For example, in the embodiment of FIG. 2, the control unit (120) can calculate the number of charging peaks included in the first capacity section (R1) of the first differential profile (D1) as three.

[0145] For example, in the embodiment of FIG. 3, the control unit (120) can calculate the number of discharge peaks included in the second capacity section (R2) of the second differential profile (D2) as 2.

[0146] The battery diagnosis step (S300) is a step for diagnosing the state of the battery based on the number of charging peaks and discharging peaks, and can be performed by the control unit (120).

[0147] Specifically, the control unit (120) may be configured to compare the sum of the number of charging peaks and discharging peaks with a preset reference number, and diagnose the state of the battery as a BOL state, MOL state, or EOL state based on the comparison result.

[0148] For example, in the embodiments of FIGS. 2 and 3, the sum of the charging peaks and the discharging peaks is 5. The control unit (120) can compare the sum of the numbers with the reference number to diagnose the battery status as a BOL state.

[0149]

[0150] 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.

[0151] 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.

[0152] 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.

[0153] (Explanation of symbols)

[0154] 10: Battery pack

[0155] 11: Battery

[0156] 12: Measurement section

[0157] 100: Battery Diagnostic Device

[0158] 110: Profile acquisition section

[0159] 120: Control unit

[0160] 130: Storage

Claims

1. A profile acquisition unit configured to acquire a first differential profile based on the differential voltage and capacity of the battery corresponding to the charging process and a second differential profile based on the differential voltage and capacity of the battery corresponding to the discharging process; and A battery diagnosis device characterized by including a control unit configured to calculate the number of charging peaks included in a first capacity section in the first differential profile, calculate the number of discharging peaks included in a second capacity section in the second differential profile, and diagnose the state of the battery according to the number of charging peaks and the number of discharging peaks.

2. In paragraph 1, The above control unit, A battery diagnosis device characterized in that it is configured to compare the sum of the number of the charging peaks and the discharging peaks with a preset reference number and diagnose the state of the battery based on the comparison result.

3. In paragraph 2, The above control unit, A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as a BOL state, a MOL state, or an EOL state based on the result of the comparison.

4. In paragraph 2, The above control unit, If the above total number is greater than or equal to the preset first reference number, the status of the battery is diagnosed as BOL status, If the above total number is less than the first reference number and exceeds the preset second reference number, the status of the battery is diagnosed as MOL status. A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as the MOL state or the EOL state if the summed number is equal to the second reference number.

5. In paragraph 4, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the capacity of the battery if the summed number is equal to the second reference number, compare the calculated capacity with a preset reference capacity, and diagnose the state of the battery as the MOL state or EOL state based on the comparison result.

6. In paragraph 5, The above control unit, Calculate the ratio of the calculated capacity to the above standard capacity, If the calculated ratio is higher than the preset standard ratio, the status of the battery is diagnosed as the MOL status. A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as the EOL state if the calculated ratio is less than the reference ratio.

7. In paragraph 5, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the capacity of the battery based on the second differential profile.

8. In paragraph 1, The above control unit, In the first differential profile, a first capacity corresponding to the lowest differential voltage is determined, and a capacity section below the determined first capacity is set as the first capacity section. A battery diagnostic device characterized in that it is configured to determine a second capacity corresponding to the highest differential voltage in the second differential profile, and set a capacity section equal to or greater than the determined second capacity as the second capacity section.

9. In paragraph 8, The above control unit, A battery diagnostic device characterized in that it is configured to divide the entire capacity section of the battery into a lower capacity section and an upper capacity section, determine the first capacity in the lower capacity section of the first differential profile, and determine the second capacity in the upper capacity section of the second differential profile.

10. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 9.

11. A profile acquisition step of acquiring a first differential profile based on the differential voltage and capacity of the battery corresponding to the charging process and a second differential profile based on the differential voltage and capacity of the battery corresponding to the discharging process; A peak count calculation step for calculating the number of charging peaks included in the first capacity section in the first differential profile and calculating the number of discharging peaks included in the second capacity section in the second differential profile; and A battery diagnosis method, characterized by including a battery diagnosis step of diagnosing the state of the battery based on the number of the charging peaks and the discharging peaks.

Images