Apparatus and method for diagnosing battery

Abstract

A battery diagnosing apparatus according to an embodiment of the present invention includes: a profile acquisition unit configured to acquire a charging profile indicating a correspondence relationship between a voltage and a current of a battery measured in a charging process; and a control unit configured to calculate a first CC capacity and a first CV capacity from the charging profile, calculate a capacity change rate for the first CC capacity and the first CV capacity on the basis of a pre-stored second CC capacity and second CV capacity, diagnosis a state of the battery on the basis of the calculated capacity change rate and a preconfigured correction coefficient, and configure a use condition for the battery according to a diagnosis result.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0014210, filed on January 30, 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 based on the charge capacity of the battery.

[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 charging profile indicating a correspondence between a voltage and a current of a battery measured during a charging process; and a control unit configured to calculate a first CC capacity and a first CV capacity from the charging profile, calculate a capacity change rate for the first CC capacity and the first CV capacity based on a second CC capacity and a second CV capacity stored in advance, diagnose a state of the battery based on the calculated capacity change rate and a preset correction coefficient, and set a usage condition for the battery based on the diagnosis result.

[0009] The control unit may be configured to calculate a CC capacity difference between the first CC capacity and the second CC capacity, calculate a CV capacity difference between the first CV capacity and the second CV capacity, and calculate a ratio of the CC capacity difference and the CV capacity difference to calculate the capacity change rate.

[0010] The control unit may be configured to calculate a decrease in the first CC capacity with respect to the second CC capacity as the CC capacity difference, and to calculate an increase in the first CV capacity with respect to the second CV capacity as the CV capacity difference.

[0011] The above control unit may be configured to multiply the capacity change rate by the correction coefficient to calculate a correction change rate, compare the correction change rate with a preset threshold value, and diagnose the state of the battery based on the comparison result.

[0012] The control unit may be configured to diagnose the state of the battery as normal if the correction change rate is greater than or equal to the threshold value.

[0013] The control unit may be configured to diagnose the state of the battery as abnormal if the correction change rate is less than the threshold value.

[0014] The above control unit may be configured to output a notification signal to notify of a sudden drop when the state of the battery is diagnosed as the abnormal state.

[0015] The control unit may be configured to change a preset charging current for the battery if the correction change rate is less than the threshold value.

[0016] The above control unit may be configured to change the upper limit of the charging current to a value obtained by multiplying the correction change rate and the upper limit of the charging current.

[0017] The above correction factor can be preset based on the change in CC capacity and the change in CV capacity of the battery over a preset reference number of cycles.

[0018] The above correction factor can be preset as a ratio of a representative change amount of the CV capacity and a representative change amount of the CC capacity during the above reference number of cycles.

[0019] A battery pack according to another aspect of the present invention may include a battery diagnostic device according to an embodiment of the present invention.

[0020] According to another aspect of the present invention, a vehicle may include a battery diagnostic device according to an embodiment of the present invention.

[0021] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a charging profile indicating a correspondence between voltage and current of a battery measured during a charging process; a capacity calculation step of calculating a first CC capacity and a first CV capacity from the charging profile; a capacity change rate calculation step of calculating a capacity change rate for the first CC capacity and the first CV capacity based on a second CC capacity and a second CV capacity stored in advance; a diagnosis step of diagnosing a state of the battery based on the calculated capacity change rate and a preset correction coefficient; and a use condition setting step of setting use conditions for the battery based on a diagnosis result.

[0022] According to one aspect of the present invention, the battery diagnosis device has the advantage of being able to non-destructively diagnose the state of the battery through a simple method because it diagnoses the state of the battery from the CC capacity and CV capacity using a correction factor.

[0023] In addition, according to one aspect of the present invention, there is an advantage in that a battery with a high possibility of sudden drop can be detected early.

[0024] 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.

[0025] 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.

[0026] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0027] FIG. 2 is a diagram schematically illustrating a charging profile according to one embodiment of the present invention.

[0028] Figures 3 to 5 are schematic diagrams illustrating the diagnostic results for the first to third batteries.

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

[0030] Figure 7 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0031] FIG. 8 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038]

[0039] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0040] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0041] Referring to FIG. 1, a battery diagnostic device (100) may include a profile acquisition unit (110) and a control unit (120).

[0042] 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.

[0043] The profile acquisition unit (110) can be configured to acquire a charging profile (CP) indicating a correspondence between the voltage and current of the battery measured during the charging process.

[0044] For example, a charge profile (CP) is a profile that represents the relationship between the voltage (V) and current (C) when the battery's SOC is charged from a preset start SOC or 0% to a preset end SOC or 100%. In other words, a charge profile (CP) represents the relationship between the battery's charging voltage and charging current.

[0045] For example, there are no specific restrictions on the charge C-rate for generating a charge profile (CP). However, to obtain a more accurate charge profile (CP), the battery should preferably be charged at a low rate. For example, a charge profile (CP) can be generated during the process of charging a battery at 0.05C.

[0046] For example, the profile acquisition unit (110) can directly receive the charging profile (CP) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the charging profile (CP) by being connected to the outside via wire and / or wirelessly and receiving the charging profile (CP).

[0047] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage and current of the battery. Furthermore, the profile acquisition unit (110) can generate a charging profile (CP) based on the received battery information. That is, the profile acquisition unit (110) can acquire a charging profile (CP) by directly generating the charging profile (CP) based on the battery information.

[0048] FIG. 2 is a diagram schematically illustrating a charging profile (CP) according to one embodiment of the present invention.

[0049] For example, in the embodiment of FIG. 2, the battery may be charged until its voltage reaches from 3.0 [V] to 4.2 [V]. Specifically, the battery may be charged with a constant current (CC) until a time point (t1) when the voltage reaches a preset threshold voltage (Vth), and may be charged with a constant voltage (CV) from the time point t1 until the end time point (t2). Here, the threshold voltage (Vth) may also be a cut-off voltage.

[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) via wire and / or wirelessly. The profile acquisition unit may transmit the acquired charging profile (CP) to the control unit (120).

[0051] The control unit (120) can be configured to calculate the first CC capacity and the first CV capacity from the charge profile (CP).

[0052] Specifically, the control unit (120) can calculate the first CC capacity and the first CV capacity of the battery from the charge profile (CP) using the ampere counting method (or coulomb counting method). Here, the first CC capacity is the charge capacity while the battery is being CC charged, and the first CV capacity is the charge capacity while the battery is being CV charged.

[0053] For example, in the embodiment of FIG. 2, the control unit (120) can calculate the first CC capacity by integrating the current amount at points 0 to t1. In addition, the control unit (120) can calculate the first CV capacity by integrating the current amount at points t1 to t2.

[0054] The control unit (120) can be configured to calculate a capacity change rate for the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and the second CV capacity.

[0055] Specifically, the second CC capacity is the CC capacity of the battery stored in advance, and means the CC capacity of the battery calculated at the previous point in time. Similarly, the second CV capacity is the CV capacity of the battery stored in advance, and means the CV capacity of the battery calculated at the previous point in time. For example, assume that the present is the nth cycle (where n is a natural number greater than or equal to 2). The control unit (120) can calculate the first CC capacity and the first CV capacity in the nth cycle. In addition, the CC capacity calculated in the n-1th cycle may be the second CC capacity stored in advance, and the calculated CV capacity may be the second CV capacity stored in advance. In this embodiment, it is described that the cycle in which the second CC capacity and the second CV capacity are calculated (the n-1th cycle) and the cycle in which the first CC capacity and the first CV capacity are calculated (the nth cycle) are 1 cycle apart, but it should be noted that the cycle gap may change depending on the diagnosis cycle, diagnosis conditions, or diagnosis method of the battery.

[0056] Specifically, the control unit (120) may be configured to calculate the CC capacity difference between the first CC capacity and the second CC capacity.

[0057] Preferably, the CC capacity may decrease as the battery degrades. Since the second CC capacity is calculated before the first CC capacity, the second CC capacity may be greater than the first CC capacity. Accordingly, the control unit (120) may be configured to calculate the amount of decrease in the first CC capacity relative to the second CC capacity as the CC capacity difference. For example, the control unit (120) may calculate the CC capacity difference by calculating the formula "second CC capacity - first CC capacity."

[0058] And, the control unit (120) can be configured to calculate the CV capacity difference between the first CV capacity and the second CV capacity.

[0059] Preferably, the CV capacity may increase as the battery degrades. Since the second CV capacity is calculated before the first CV capacity, the second CV capacity may be less than or equal to the first CV capacity. Accordingly, the control unit (120) may be configured to calculate the increase in the first CV capacity relative to the second CV capacity as the CV capacity difference. For example, the control unit (120) may calculate the CV capacity difference by calculating the formula "first CV capacity - second CV capacity."

[0060] Finally, the control unit (120) can be configured to calculate the ratio of the CC capacity difference and the CV capacity difference to produce a capacity change rate.

[0061] For example, the control unit (120) can calculate the capacity change rate by calculating the ratio of the CV capacity difference to the CC capacity difference. That is, the control unit (120) can calculate the capacity change rate by calculating the formula “CV capacity difference ÷ CC capacity difference.”

[0062] As another example, the control unit (120) can calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference. That is, the control unit (120) can calculate the capacity change rate by calculating the formula “CC capacity difference ÷ CV capacity difference.”

[0063] In the following, for convenience of explanation, it is assumed that the capacity change rate is the ratio of the CV capacity difference to the CC capacity difference.

[0064] The control unit (120) can be configured to diagnose the state of the battery based on the calculated capacity change rate and a preset correction coefficient.

[0065] Specifically, the control unit (120) may be configured to calculate a correction change rate by multiplying the capacity change rate by a correction coefficient. That is, the correction change rate is a value obtained by multiplying the capacity change rate by the correction coefficient.

[0066] For example, the control unit (120) can calculate the correction change rate using Equation 1 below.

[0067] [Formula 1]

[0068]

[0069] Here, n is a natural number greater than or equal to 2, and is a factor indicating the cycle point. CC n is the correction change rate of the nth cycle, and QV n is the first CV capacity of the nth cycle, and QV n-1 is the second CV capacity of the nth cycle. QC n is the first CC capacity of the nth cycle, and QC n-1 is the second CC capacity of the n-1 cycle, and α is the correction factor. And, the capacity change rate is "(QV n -QV n-1 )÷(QC n-1 -QC n )"am.

[0070] In addition, the correction factor can be preset based on the change in CC capacity and the change in CV capacity of the battery over a preset reference number of cycles.

[0071] Specifically, the correction factor can be preset as a ratio of a representative change in CV capacity and a representative change in CC capacity during a reference number of cycles.

[0072] Preferably, the correction factor can be set for a battery in the beginning of life (BOL) state. That is, the correction factor can be set based on the representative change in CV capacity and the representative change in CC capacity over a reference number of cycles from the first cycle of the battery. Here, the representative change may be the minimum change, maximum change, average change, or median change.

[0073] For example, assuming that the preset reference number is 10 times and the representative change amount is the average change amount. The change amount of CV capacity and the change amount of CC capacity from the 1st cycle (the initial cycle) to the 10th cycle of the battery can be calculated. Here, since the change amount of CV capacity and the change amount of CV capacity are calculated for each cycle from the 2nd cycle, a total of 9 changes in CV capacity and changes in CC capacity can be calculated. The average value of the 9 changes in CV capacity can be set as the representative change amount of CV capacity, and the average value of the 9 changes in CC capacity can be set as the representative change amount of CC capacity. In addition, a correction coefficient can be set according to the ratio of the average value of the change amount of CV capacity and the average value of the change amount of CC capacity.

[0074] For example, the correction factor can be preset according to Equation 2 below.

[0075] [Formula 2]

[0076]

[0077] Here, α is the correction factor, and dQC ref is the representative change in CC capacity, and dQV ref is a representative change in CV capacity.

[0078] The control unit (120) may be configured to compare the correction change rate with a preset threshold value (th) and diagnose the state of the battery based on the comparison result.

[0079] Specifically, the control unit (120) can compare the magnitude of the correction change rate and the threshold value (th). Here, the threshold value (th) is a measure that distinguishes the state of the battery as normal or abnormal depending on the correction change rate.

[0080] For example, the control unit (120) can diagnose the battery's condition as normal if the correction change rate is greater than or equal to a threshold value (th). As another example, the control unit (120) can be configured to diagnose the battery's condition as abnormal if the correction change rate is less than the threshold value (th).

[0081] In theory, as the CC capacity decreases as the battery degrades, the CV capacity should increase by the amount of the decrease. However, in reality, as the battery degrades, the CV capacity does not increase by the amount of the decrease in the CC capacity. Therefore, the control unit (120) corrects the capacity change rate calculated for the nth cycle and the n-1th cycle with a correction factor, and determines whether the battery degrades at a normal or abnormal level based on the corrected change rate.

[0082] For example, it is assumed that the average change amount (average decrease amount) of CC capacity is 1, the average change amount (average increase amount) of CV capacity is 0.5, and the threshold value (th) is set to 1. In this case, according to Equation 2, the correction factor can be preset to 2. The control unit (120) can diagnose the state of the battery as normal if the correction change rate calculated by multiplying the capacity change rate and the correction factor is 1 or more. Conversely, the control unit (120) can diagnose the state of the battery as abnormal if the correction change rate is less than 1.

[0083] That is, if the correction change rate multiplied by the correction coefficient is less than the threshold value (th), the balance between the decrease in CC capacity and the increase in CV capacity is significantly broken. Therefore, in this case, the control unit (120) can diagnose the battery status as abnormal.

[0084] Since the battery diagnosis device (100) diagnoses the state of the battery from the CC capacity and CV capacity using a correction factor, it has the advantage of being able to non-destructively diagnose the state of the battery in a simple manner.

[0085]

[0086] 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 the control unit (120), and may be connected to the profile acquisition unit (110) and the control unit (120) by various well-known means.

[0087] 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 able to record, erase, update, and read data. As an example, the information storage means may include a random access memory (RAM), a flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a register, 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).

[0088]

[0089] The control unit (120) may be configured to output a notification signal to warn of a sudden drop when the battery is diagnosed as being in an abnormal state.

[0090] Specifically, batteries diagnosed as abnormal exhibit a greater rate of decrease in CC capacity than an increase in CV capacity. This suggests that batteries diagnosed as abnormal may be experiencing a rapid deterioration in their lifespan. Therefore, batteries diagnosed as abnormal are highly susceptible to sudden drop at unexpected moments.

[0091] If a battery is installed and used in a device such as a bicycle, motorcycle, vehicle, drone, or ESS, a sudden battery drop could cause the device to shut down. For example, a sudden battery drop could cause the vehicle or other transportation device to shut down, potentially resulting in personal injury. Similarly, if a device such as a drone shuts down, it could result in financial losses, such as damage and / or loss of the device. Furthermore, damage to these devices could also result in personal injury.

[0092] Accordingly, the battery diagnostic device (100) has the advantage of being able to prevent unexpected accidents caused by sudden drops in the battery in advance by determining the possibility of sudden drops in the battery based on the CC capacity and CV capacity that can be easily obtained from the charge profile (CP). In addition, the battery diagnostic device (100) can provide a warning about a battery with a high possibility of sudden drops by externally outputting a notification signal regarding the diagnosis result.

[0093]

[0094] Figures 3 to 5 are schematic diagrams illustrating the diagnostic results for the first to third batteries.

[0095] Specifically, the first battery is designed to degrade more slowly as the cycle progresses, the second battery is designed to degrade at a normal level as the cycle progresses, and the third battery is designed to degrade more rapidly as the cycle progresses.

[0096] In the embodiment of FIG. 3, the first profile (P1) is a profile representing a cycle-by-cycle correction change rate for the first battery, the second profile (P2) is a profile representing a cycle-by-cycle correction change rate for the second battery, and the third profile (P3) is a profile representing a cycle-by-cycle correction change rate for the third battery.

[0097] The control unit (120) can diagnose the condition of the batteries by comparing the cycle-by-cycle correction change rate of the first to third batteries with a preset threshold value (th). The first battery may be diagnosed as normal throughout the cycle, the second battery may be diagnosed as abnormal for the first time at cycle 350, and the third battery may be diagnosed as abnormal for the first time at cycle 200.

[0098] In the embodiment of FIG. 4, the fourth profile (P4) is a profile representing the state of health (SOH) per cycle for the first battery, the fifth profile (P5) is a profile representing the SOH per cycle for the second battery, and the sixth profile (P6) is a profile representing the SOH per cycle for the third battery.

[0099] The control unit (120) can diagnose the state of the batteries by comparing the cycle-by-cycle SOH of the first to third batteries with a preset first threshold value (th1). Here, the first threshold value (th1) can be preset as a reference SOH that can distinguish the state of the batteries as normal or abnormal. The first battery can be diagnosed as normal throughout the cycle, the second battery can be diagnosed as abnormal for the first time at the 400th cycle, and the third battery can be diagnosed as abnormal for the first time at the 300th cycle.

[0100] In addition, the control unit (120) can diagnose the state of the batteries by comparing the SOH change rate per cycle of the first to third batteries with a preset second threshold value (th2). Here, the second threshold value (th2) can be preset as a reference SOH change rate that can distinguish the state of the batteries as normal or abnormal. The first battery can be diagnosed as normal throughout the cycle, the second battery can be diagnosed as abnormal for the first time at cycle 370, and the third battery can be diagnosed as abnormal for the first time at cycle 250.

[0101] Referring to FIG. 5, it can be seen that when diagnosing the battery condition based on the compensation change rate among the compensation change rate, SOH, and SOH change rate, the cycle in which the abnormal condition is first diagnosed is the earliest. Therefore, according to one embodiment of the present invention, there is an advantage in that a battery with a high probability of sudden drop can be detected early.

[0102]

[0103] The control unit (120) may be configured to set usage conditions for the battery based on the diagnosis results. Here, the usage conditions are conditions used for operating the battery, and may include charging current, allowable temperature, available voltage, and available SOC.

[0104] Specifically, the control unit (120) may be configured to change the preset charging current for the battery if the compensation change rate is below a threshold value. Since the compensation change rate is a value related to the decrease in CC capacity and the increase in CV capacity when the battery is charged, the usage conditions related to charging must be controlled in order to reduce the possibility of sudden drop in the battery. In particular, among the usage conditions related to charging, changing the usage conditions directly related to CC capacity and CV capacity is an appropriate measure for the battery. Therefore, the control unit (120) may change the preset charging current for the battery if the battery condition is diagnosed as abnormal.

[0105] Preferably, the control unit (120) can reduce the preset charging current for the battery. Since a reduced charging current reduces overvoltage, the time it takes for the battery voltage to reach the threshold voltage (Vth) can increase. In other words, due to the reduced overvoltage, a reduced charging current can increase the CC capacity compared to before.

[0106] In order to reduce the preset charging current, the control unit (120) may change the upper limit of the charging current based on the compensation change rate. For example, the control unit (120) may be configured to change the upper limit of the charging current to a value obtained by multiplying the compensation change rate and the upper limit of the charging current. That is, since the compensation change rate is a value less than a threshold value (e.g., 1), the value obtained by multiplying the upper limit of the preset charging current by the compensation change rate may be smaller than the upper limit of the preset charging current.

[0107] In addition, the compensation change rate is a factor that reflects the capacity change behavior of the battery. Therefore, the control unit (120) can change the upper limit of the charging current set for the battery to correspond to the capacity change behavior of the battery by reducing the upper limit of the preset charging current using the compensation change rate.

[0108] That is, the battery diagnostic device (100) can rapidly diagnose the condition of the battery based on the compensation change rate and significantly reduce the possibility of sudden battery drop by changing the upper limit of the charging current for the battery from the diagnosis point in time. Therefore, according to the battery diagnostic device (100), the expected lifespan of the battery can be increased.

[0109]

[0110] 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.

[0111] 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.

[0112] FIG. 6 is a schematic drawing of a battery pack (10) according to another embodiment of the present invention.

[0113] 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).

[0114] 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).

[0115] 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.

[0116] 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 charging profile (CP) based on the battery information.

[0117] As another example, the profile acquisition unit (110) can receive a charging profile (CP) from the measurement unit (12).

[0118] An external device may be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (10). For example, the external device may 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) may be electrically connected.

[0119]

[0120] FIG. 7 is a schematic drawing of a vehicle (700) according to another embodiment of the present invention.

[0121] Referring to FIG. 7, a battery pack (710) according to an embodiment of the present invention may be included in a vehicle (700), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (710) may drive the vehicle (700) by supplying power to a motor through an inverter provided in the vehicle (700). Here, the battery pack (710) may include a battery diagnostic device (100). That is, the vehicle (700) may include a battery diagnostic device (100). In this case, the battery diagnostic device (100) may be an onboard device included in the vehicle (700).

[0122]

[0123] FIG. 8 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0124] Referring to FIG. 8, the battery diagnosis method may include a profile acquisition step (S100), a capacity calculation step (S200), a capacity change rate calculation step (S300), a diagnosis step (S400), and a usage condition setting step (S500).

[0125] 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.

[0126] The profile acquisition step (S100) is a step of acquiring a charging profile (CP) that indicates the correspondence between the voltage and current of the battery measured during the charging process, and can be performed by the profile acquisition unit (110).

[0127] For example, the profile acquisition unit (110) can directly receive the charging profile (CP) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the charging profile (CP) by being connected to the outside via wire and / or wirelessly and receiving the charging profile (CP).

[0128] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage and current of the battery. Furthermore, the profile acquisition unit (110) can generate a charging profile (CP) based on the received battery information. That is, the profile acquisition unit (110) can acquire a charging profile (CP) by directly generating the charging profile (CP) based on the battery information.

[0129] The capacity calculation step (S200) is a step of calculating the first CC capacity and the first CV capacity from the charging profile (CP), and can be performed by the control unit (120).

[0130] For example, the control unit (120) can calculate the first CC capacity and the first CV capacity of the battery from the charge profile (CP) using the ampere counting method or coulomb counting method.

[0131] The capacity change rate calculation step (S300) is a step of calculating the capacity change rate for the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and the second CV capacity, and can be performed by the control unit (120).

[0132] For example, the control unit (120) can calculate the CC capacity difference between the first CC capacity and the second CC capacity, calculate the CV capacity difference between the first CV capacity and the second CV capacity, and calculate the ratio of the CC capacity difference and the CV capacity difference to calculate the capacity change rate.

[0133] The diagnosis step (S400) is a step for diagnosing the state of the battery based on the calculated capacity change rate and a preset correction coefficient, and can be performed by the control unit (120).

[0134] For example, the control unit (120) can calculate a correction change rate by multiplying the capacity change rate by a correction coefficient. Furthermore, if the correction change rate is greater than or equal to a threshold value (th), the control unit (120) can diagnose the battery's condition as normal. Conversely, if the correction change rate is less than the threshold value (th), the control unit (120) can diagnose the battery's condition as abnormal.

[0135] The usage condition setting step (S500) is a step of setting usage conditions for the battery based on the diagnosis results, and can be performed by the control unit (120).

[0136] For example, the control unit (120) may be configured to change the upper limit of the charging current to a value obtained by multiplying the correction change rate and the upper limit of the charging current.

[0137]

[0138] 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.

[0139] 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.

[0140] 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.

[0141]

[0142] (Explanation of symbols)

[0143] 10: Battery pack

[0144] 11: Battery

[0145] 12: Measurement section

[0146] 100: Battery Diagnostic Device

[0147] 110: Profile acquisition section

[0148] 120: Control unit

[0149] 130: Storage

[0150] 400: Car

[0151] 410: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a charging profile indicating a correspondence between the voltage and current of the battery measured during the charging process; and A battery diagnosis device characterized by including a control unit configured to calculate a first CC capacity and a first CV capacity from the charging profile, calculate a capacity change rate for the first CC capacity and the first CV capacity based on a pre-stored second CC capacity and a pre-set correction coefficient, diagnose the state of the battery based on the calculated capacity change rate and a pre-set correction coefficient, and set a usage condition for the battery based on the diagnosis result.

2. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the CC capacity difference between the first CC capacity and the second CC capacity, calculate the CV capacity difference between the first CV capacity and the second CV capacity, and calculate the capacity change rate by calculating the ratio of the CC capacity difference and the CV capacity difference.

3. In paragraph 2, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the amount of decrease in the first CC capacity with respect to the second CC capacity as the CC capacity difference, and to calculate the amount of increase in the first CV capacity with respect to the second CV capacity as the CV capacity difference.

4. In paragraph 1, The above control unit, A battery diagnosis device characterized in that it is configured to multiply the capacity change rate by the correction coefficient to calculate a correction change rate, compare the correction change rate with a preset threshold value, and diagnose the state of the battery based on the comparison result.

5. In paragraph 4, The above control unit, If the above correction change rate is greater than or equal to the threshold value, the state of the battery is diagnosed as normal, A battery diagnosis device characterized in that it is configured to diagnose the state of the battery as abnormal if the correction change rate is less than the threshold value.

6. In paragraph 5, The above control unit, A battery diagnostic device characterized in that it is configured to output a notification signal to notify a sudden drop warning when the state of the battery is diagnosed as the abnormal state.

7. In paragraph 4, The above control unit, A battery diagnostic device characterized in that it is configured to change a preset charging current for the battery when the above correction change rate is less than the threshold value.

8. In paragraph 7, The above control unit, A battery diagnostic device characterized in that it is configured to change the upper limit of the charging current to a value obtained by multiplying the correction change rate and the upper limit of the charging current.

9. In paragraph 1, The above correction factor is, A battery diagnostic device characterized in that it is preset based on the change in CC capacity and the change in CV capacity of the battery during a preset reference number of cycles.

10. In paragraph 9, The above correction factor is, A battery diagnostic device characterized in that the ratio of the representative change amount of the CV capacity and the representative change amount of the CC capacity during the above-mentioned reference number of cycles is preset.

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

12. A vehicle including a battery diagnostic device according to any one of claims 1 to 10.

13. A profile acquisition step for acquiring a charging profile representing the correspondence between the voltage and current of the battery measured during the charging process; A capacity calculation step for calculating the first CC capacity and the first CV capacity from the above charging profile; A capacity change rate calculation step for calculating a capacity change rate for the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and the second CV capacity; A diagnostic step for diagnosing the condition of the battery based on the calculated capacity change rate and a preset correction coefficient; and A battery diagnosis method characterized by including a usage condition setting step of setting usage conditions for the battery based on the diagnosis result.

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