Apparatus and method for diagnosing battery

Abstract

An apparatus for diagnosing a battery, according to one embodiment of the present invention, comprises: a voltage measurement unit for measuring voltages of a plurality of batteries; and a control unit calculating voltage deviation of the plurality of batteries according to the plurality of measured voltages, calculating the voltage deviation change amount of each of the plurality of batteries on the basis of the calculated voltage deviation, comparing the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount, and diagnosing the state of each of the plurality of batteries according to the comparison result.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2023-0098509, filed on July 27, 2023, and all contents 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 capable of diagnosing an internal micro-short circuit 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] If a micro-short circuit occurs within a battery, leakage current can occur within that battery. For example, suppose multiple batteries are included in a battery pack. If a micro-short circuit occurs within one battery, resulting in leakage current, that battery's voltage may gradually decrease compared to the voltages of the other batteries. If this phenomenon persists, a hard short circuit can occur, potentially causing permanent damage to the battery pack.

[0006] Therefore, it is necessary to develop a technology that can diagnose in advance whether a micro-short circuit has occurred inside the battery.

[0007] The present invention has been devised to solve the above problems, and its purpose is to provide a battery diagnostic device and method capable of diagnosing whether an internal micro-short circuit has occurred in a battery.

[0008] 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.

[0009] A battery diagnosis device according to one aspect of the present invention may include a voltage measurement unit configured to measure the voltages of a plurality of batteries; and a control unit configured to calculate voltage deviations of the plurality of batteries based on the measured voltages, calculate a voltage deviation change amount of each of the plurality of batteries based on the calculated voltage deviations, compare the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount, and diagnose the status of each of the plurality of batteries based on the comparison result.

[0010] The above control unit may be configured to calculate a voltage deviation change amount of each of the plurality of batteries based on a difference between the voltage deviation calculated at the current point in time and a previous voltage deviation calculated at a previous point in time.

[0011] The control unit may be configured to calculate the amount of change in voltage deviation by normalizing the difference between the voltage deviation and the previous voltage deviation to the difference between the current point in time and the previous point in time.

[0012] The control unit may be configured to calculate a difference in voltage deviation by calculating a difference between the voltage deviation and the previous voltage deviation, calculate a difference in time by calculating a difference between the current time and the previous time, and calculate a change in voltage deviation for a unit time by dividing the difference in voltage deviation by the difference in time.

[0013] The above control unit may be configured to diagnose the state of a battery in which the voltage deviation change amount is greater than the reference change amount as an abnormal state.

[0014] The above control unit may be configured to diagnose the state of the battery in which the voltage deviation change amount is less than the reference change amount as a normal state.

[0015] The above control unit may be configured to calculate the number of times the voltage deviation change amount is greater than the reference change amount, and to diagnose the state of the battery when the calculated number of times reaches a preset reference number as being abnormal.

[0016] The above control unit may be configured to diagnose that an internal micro-short circuit has occurred in the battery diagnosed as being in the abnormal state.

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

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

[0019] According to another aspect of the present invention, a battery diagnosis method may include a voltage measuring step of measuring the voltages of a plurality of batteries; a voltage deviation calculation step of calculating voltage deviations of the plurality of batteries based on the plurality of voltages measured in the voltage measuring step; a voltage deviation change calculation step of calculating a voltage deviation change amount of each of the plurality of batteries based on the voltage deviations calculated in the voltage deviation calculation step; a comparison step of comparing the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount; and a diagnosis step of diagnosing a state of each of the plurality of batteries based on a comparison result of the comparison step.

[0020] According to one aspect of the present invention, a battery diagnostic device can diagnose the condition of each of a plurality of batteries by tracking trends in voltage deviation changes in the batteries. Specifically, the battery diagnostic device can quickly diagnose the presence of internal micro-short circuits in each of the plurality of batteries.

[0021] 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.

[0022] 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.

[0023] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0024] FIG. 2 is a diagram schematically illustrating voltages for a plurality of battery cells according to one embodiment of the present invention.

[0025] FIG. 3 is a diagram schematically illustrating a voltage deviation change amount according to one embodiment of the present invention.

[0026] FIG. 4 is a diagram schematically illustrating a diagnostic embodiment according to one embodiment of the present invention.

[0027] FIG. 5 is a drawing illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.

[0028] FIG. 6 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0029] FIG. 7 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036]

[0037] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0038] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0039] Referring to FIG. 1, a battery diagnostic device (100) may include a voltage measurement unit (110) and a control unit (120).

[0040] Hereinafter, 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, a battery may also refer to a battery module comprising multiple cells connected in series and / or parallel. For convenience of explanation, a battery is described below as a single, independent cell.

[0041] The voltage measuring unit (110) can be configured to measure the voltage of multiple batteries.

[0042] Specifically, the voltage measuring unit (110) may be configured to measure the voltage of each of the plurality of batteries. Preferably, the voltage measuring unit (110) may measure the open circuit voltage (OCV) of each of the plurality of batteries. For example, the voltage measuring unit (110) may measure the open circuit voltage of the plurality of batteries when charging or discharging of the plurality of batteries is completed and a rest period (rest time) has elapsed.

[0043] FIG. 2 is a diagram schematically illustrating voltages for a plurality of battery cells according to one embodiment of the present invention.

[0044] In the embodiment of Fig. 2, it is assumed that a first battery (Ba), a second battery (Bb), a third battery (Bc), and a fourth battery (Bd) are provided. The voltage measuring unit (110) can measure the voltage of the first battery (Ba) as Va, the voltage of the second battery (Bb) as Vb, the voltage of the third battery (Bc) as Vc, and the voltage of the fourth battery (Bd) as Vd.

[0045] In addition, the voltage measuring unit (110) can be connected to the control unit (120) so as to be able to communicate with it. For example, the voltage measuring unit (110) and the control unit (120) can be connected by wire and / or wirelessly. The voltage measuring unit (110) can transmit information about the measured voltage to the control unit (120).

[0046] The control unit (120) can be configured to calculate the voltage deviation of multiple batteries according to the measured multiple voltages.

[0047] Specifically, the control unit (120) can receive voltage information of multiple batteries from the voltage measurement unit (110) and calculate voltage deviations of the multiple batteries based on the received voltage information.

[0048] First, the control unit (120) may be configured to calculate the average voltage of multiple batteries. In the embodiment of FIG. 2, the control unit (120) may calculate the average voltage for the voltages of the first to fourth batteries (Ba, Bb, Bc, Bd). For example, the control unit (120) may calculate the average voltage as Vavg by calculating the formula "(Va+Vb+Vc+Vd)÷4."

[0049] Next, the control unit (120) may be configured to calculate the difference between the calculated average voltage and the voltage of each of the plurality of batteries to calculate the voltage deviation of each of the plurality of batteries. In the embodiment of FIG. 2, the control unit (120) may calculate the difference between the voltages of the first to fourth batteries (Ba, Bb, Bc, Bd) and the average voltage, to calculate the voltage deviation of the first to fourth batteries (Ba, Bb, Bc, Bd). For example, the control unit (120) may calculate the equation “|Va-Vavg|” to calculate the voltage deviation of the first battery (Ba) as dVa, and may calculate the equation “|Vb-Vavg|” to calculate the voltage deviation of the second battery (Bb) as dVb. And, the control unit (120) can calculate the voltage deviation of the third battery (Bc) as dVc by calculating the formula “|Vc-Vavg|”, and can calculate the voltage deviation of the fourth battery (Bd) as dVd by calculating the formula “|Vd-Vavg|”. Here, “||” is an absolute value symbol, and the calculated voltage deviation can be expressed as the absolute value of the difference between the voltage of the battery and the average voltage.

[0050] The control unit (120) can be configured to calculate the amount of change in voltage deviation of each of the plurality of batteries based on the calculated voltage deviation.

[0051] Specifically, the control unit (120) may be configured to calculate the voltage deviation change amount of each of the plurality of batteries based on the difference between the voltage deviation calculated at the current point in time and the previous voltage deviation calculated at the previous point in time. For example, the control unit (120) may calculate the voltage deviation and the voltage deviation change amount of each of the plurality of batteries each time the voltages of the plurality of batteries are measured by the measurement unit (110). Here, when the voltage deviations of the plurality of batteries are calculated for the first time, since the voltage deviation calculated at the previous point in time does not exist, the calculation of the voltage deviation change amount may be omitted.

[0052] FIG. 3 is a diagram schematically illustrating a voltage deviation change amount according to one embodiment of the present invention. Specifically, the embodiment of FIG. 3 is a diagram illustrating only the voltage deviation of the first battery (Ba) among the voltage deviations of the first to fourth batteries (Ba, Bb, Bc, Bd) calculated at points D1, D2, D3, and D4.

[0053] For example, in the embodiment of FIG. 3, D1, D2, D3, and D4 represent the points in time at which the voltage of the first battery (Ba) was measured. Specifically, D1, D2, D3, and D4 represent the days on which the voltage of the first battery (Ba) was measured. Here, the intervals between D1, D2, D3, and D4 may be the same or different. That is, it should be noted that the intervals between D1, D2, D3, and D4 are not limited to a predetermined cycle.

[0054] Meanwhile, although Fig. 3 only shows the voltage deviation of the first battery (Ba), it should be noted that the voltage deviations of the second to fourth batteries (Bb, Bc, Bd) were also calculated to diagnose the status of the second to fourth batteries (Bb, Bc, Bd).

[0055] In the embodiment of FIG. 3, the first voltage deviation of the first battery (Ba) calculated at time point D1 is dV1, the second voltage deviation of the first battery (Ba) calculated at time point D2 is dV2, the third voltage deviation of the first battery (Ba) calculated at time point D3 is dV3, and the fourth voltage deviation of the first battery (Ba) calculated at time point D4 is dV4. The control unit (120) can calculate the difference in voltage deviations at consecutive time points in order to calculate the amount of change in voltage deviation for the first battery (Ba). The control unit (120) can calculate the difference between the voltage deviations at time points D1 and D2 according to the formula “dV2-dV1”, and calculate the second amount of change in voltage deviation corresponding to time point D2 as △dV2. The control unit (120) can calculate the difference between the voltage deviations at point D2 and point D3 according to the formula "dV3-dV2", and calculate the third voltage deviation change amount corresponding to point D3 as △dV3. The control unit (120) can calculate the difference between the voltage deviations at point D4 and point D3 according to the formula "dV4-dV3", and calculate the fourth voltage deviation change amount corresponding to point D4 as △dV4.

[0056] The control unit (120) may be configured to compare the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount. In addition, the control unit (120) may be configured to diagnose the status of each of the plurality of batteries based on the comparison result.

[0057] Here, the reference variation can be set based on battery characteristics. Specifically, the reference variation can be set based on the battery's shape (e.g., cylindrical, pouch, or prismatic), internal materials (e.g., positive electrode material, negative electrode material, separator, and electrolyte), and specifications. For example, the reference variation can be set based on the voltage deviation change when an internal micro-short circuit occurs in a reference battery (set to correspond to the battery being diagnosed).

[0058] The control unit (120) can compare the magnitude of the voltage deviation change amount of each of the plurality of batteries with the reference change amount. For example, in the embodiment of FIG. 3, the control unit (120) can diagnose the state of the battery at time D2 by comparing the second voltage deviation change amount (△dV2) at time D2 with the reference change amount. The control unit (120) can diagnose the state of the battery at time D3 by comparing the third voltage deviation change amount (△dV3) at time D3 with the reference change amount. The control unit (120) can diagnose the state of the battery at time D4 by comparing the fourth voltage deviation change amount (△dV4) at time D4 with the reference change amount.

[0059] In addition, the control unit (120) may be configured to diagnose the state of a battery in which the voltage deviation change amount is greater than or equal to a reference change amount as an abnormal state. Conversely, the control unit (120) may be configured to diagnose the state of a battery in which the voltage deviation change amount is less than or equal to a reference change amount as a normal state.

[0060] Fig. 4 is a schematic diagram illustrating a diagnostic embodiment according to one embodiment of the present invention. Specifically, the embodiment of Fig. 4 is an embodiment in which the voltage deviation change amount (△dV2, △dV3, △dV4) of the first battery according to the embodiment of Fig. 3 is compared with the reference change amount (TH).

[0061] For example, in the embodiment of FIG. 4, since the second voltage deviation change amount (△dV2) and the third voltage deviation change amount (△dV3) are smaller than the reference change amount (TH), the control unit (120) can diagnose the state of the battery as normal at time points D2 and D3. Since the fourth voltage deviation change amount (△dV4) is larger than the reference change amount (TH), the control unit (120) can diagnose the state of the battery as abnormal at time points D4.

[0062] The battery diagnostic device (100) according to one embodiment of the present invention has the advantage of being able to immediately diagnose the battery's condition by considering the amount of voltage deviation change from the previous time point at each diagnostic point. In other words, the battery diagnostic device (100) has the advantage of being able to quickly diagnose the battery's condition even without considering long-term trends in battery condition changes.

[0063] In addition, the battery diagnosis device (100) primarily determines the relative voltage behavior (voltage deviation) of multiple batteries, and secondarily determines the change in the relative voltage behavior (voltage deviation change amount) over time for each battery. That is, since the battery diagnosis device (100) diagnoses the status of multiple batteries by considering both the relative voltage behavior of multiple batteries and the change in the voltage behavior of each battery, it has the advantage of being able to diagnose the status of multiple batteries more accurately.

[0064]

[0065] Meanwhile, 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 control unit (120) may be implemented as a set of program modules. In this case, the program modules may be stored in a memory and executed by the control unit (120). The memory may be located inside or outside the control unit (120) and may be connected to the control unit (120) by various well-known means.

[0066] 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 control unit (120).

[0067]

[0068] The control unit (120) can be configured to calculate the amount of change in voltage deviation by normalizing the difference between the voltage deviation and the previous voltage deviation to the difference between the current point in time and the previous point in time.

[0069] Specifically, the control unit (120) can diagnose the status of the plurality of batteries based on the timing at which the measurement unit (110) measures the voltage of the plurality of batteries. Here, if the measurement unit (110) measures the voltage irregularly, the difference between the previous time point and the current time point may not be constant. In addition, if the measurement unit (110) measures the voltage periodically but the measurement cycle is too long, the amount of voltage deviation change of each of the plurality of batteries is bound to increase. Therefore, the control unit (120) can diagnose the status of the plurality of batteries more accurately by calculating the amount of voltage deviation change per unit time point for each of the plurality of batteries.

[0070] The control unit (120) may be configured to calculate the difference in voltage deviation by calculating the difference between the voltage deviation and the previous voltage deviation. For example, in the embodiment of FIG. 3, the control unit (120) may calculate the difference between the first voltage deviation (dV1) and the second voltage deviation (dV2) at time D2, thereby calculating the second voltage deviation change amount (△dV2).

[0071] The control unit (120) may be configured to calculate the time difference by calculating the difference between the current time point and the previous time point. For example, in the embodiment of FIG. 3, the control unit (120) may calculate the time difference (dD12) between time points D2 and D1.

[0072] The control unit (120) may be configured to calculate the voltage deviation change amount for a unit point in time by dividing the difference in voltage deviation by the difference in time. For example, in the embodiment of FIG. 3, the control unit (120) may calculate the equation “second voltage deviation change amount (△dV2) ÷ difference in time (D2-D1)” to calculate the voltage deviation change amount for a unit point in time. The control unit (120) may calculate the equation “third voltage deviation change amount (△dV3) ÷ difference in time (D3-D2)” to calculate the third voltage deviation change amount for a unit point in time. The control unit (120) may calculate the equation “fourth voltage deviation change amount (△dV4) ÷ difference in time (D4-D3)” to calculate the fourth voltage deviation change amount for a unit point in time. If time points D1, D2, D3, and D4 are time points per day, the control unit (120) may calculate the daily voltage deviation change amount.

[0073] Since the battery diagnosis device (100) diagnoses the state of the battery based on the amount of voltage deviation change for each point in time, the possibility of misdiagnosis of the battery state due to the time difference between the previous point in time and the current point in time can be reduced.

[0074]

[0075] The control unit (120) may be configured to calculate the number of times the voltage deviation change amount is greater than or equal to a reference change amount. In addition, the control unit (120) may be configured to diagnose the state of a battery in which the calculated number of times reaches a preset reference number as being abnormal.

[0076] Here, the reference number is set to prevent the battery's condition from being incorrectly diagnosed. For example, the reference number may be set to three. In this case, the control unit (120) can diagnose the battery's condition as abnormal if the number of times the voltage deviation variation exceeds the reference variation reaches three.

[0077] For example, the voltages of multiple batteries may be inaccurate due to measurement noise, etc. If the battery status is diagnosed based on inaccurate voltages, there is a risk of the battery status being incorrectly diagnosed. Therefore, to prevent the battery status from being incorrectly diagnosed due to unexpected noise, etc., the battery diagnosis device (100) can diagnose the battery status by further considering the number of times the voltage deviation change amount exceeds a reference change amount.

[0078]

[0079] The control unit (120) may be configured to diagnose that an internal micro-short circuit has occurred in a battery diagnosed as being in an abnormal state.

[0080] Typically, the presence of internal micro-shorts can be determined by observing the battery's voltage behavior over time. That is, the battery's condition is diagnosed by considering long-term trends in battery voltage. This is because internal micro-shorts are difficult to detect immediately based on the voltage behavior of a single battery. However, internal micro-shorts worsen over time, and these worsening internal shorts can lead to performance degradation and damage.

[0081] The battery diagnostic device (100) has the advantage of being able to quickly diagnose the status of a battery without having to check the long-term voltage behavior of each battery by considering the voltage deviation between multiple batteries and the amount of voltage deviation change of each battery. In other words, the battery diagnostic device (100) has the advantage of being able to prevent problems such as performance degradation or hard short circuits from occurring in the battery in unexpected situations by quickly diagnosing the status of the battery.

[0082]

[0083] In one embodiment, the control unit (120) may cut off the electrical connection between a battery diagnosed as abnormal (hereinafter, “abnormal battery”) and a battery diagnosed as normal (hereinafter, “normal battery”). That is, the control unit (120) may electrically isolate the abnormal battery from the normal battery by detecting that a micro-internal short circuit has occurred. For example, the control unit (120) may control a switching element corresponding to the abnormal battery to be turned off. As another example, the control unit (120) may blow a fuse corresponding to the abnormal battery.

[0084] In another embodiment, the control unit (120) may output information about an abnormal battery to an external device. For example, the control unit (120) may output information about an abnormal battery to an external display device or alarm device. Accordingly, users and others can quickly access information about an abnormal battery.

[0085]

[0086] 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 voltage measurement unit (110), control unit (120), and storage unit (130) of the battery diagnosis device (100) can be implemented as components of the BMS.

[0087] In addition, the battery diagnostic device (100) according to the present invention may be equipped in a battery pack (10). That is, the battery pack (10) according to the present invention may include the above-described battery diagnostic device (100) and one or more battery cells. In addition, the battery pack (10) may further include electrical components (relays, fuses, etc.) and a case, etc.

[0088] FIG. 5 is a drawing illustrating an exemplary configuration of a battery pack (10) according to another embodiment of the present invention. Preferably, the battery pack (10) may include a battery diagnostic device (100).

[0089] The battery pack (10) may include a first battery (Ba), a second battery (Bb), a third battery (Bc), and a fourth battery (Bd). For example, in the embodiment of FIG. 5, the first battery (Ba), the second battery (Bb), the third battery (Bc), and the fourth battery (Bd) may be connected in series. However, it should be noted that the number of batteries included in the battery pack (10) and the connection relationship (series and / or parallel) of the batteries are not limited by the embodiment of FIG. 5.

[0090] The positive terminal of the first battery (Ba) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the fourth battery (Bd) can be connected to the negative terminal (P-) of the battery pack (10).

[0091] The voltage measurement unit (110) can be connected to the first sensing line (SL1), the second sensing line (SL2), the third sensing line (SL3), the fourth sensing line (SL4), and the fifth sensing line (SL5).

[0092] Specifically, the voltage measuring unit (110) may be connected to the positive terminal of the first battery (Ba) through the first sensing line (SL1) and may be connected to the negative terminal of the first battery (Ba) through the second sensing line (SL2). The voltage measuring unit (110) may measure the voltage of the first battery (Ba) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0093] Likewise, the voltage measuring unit (110) can measure the voltage of the second battery (Bb) through the second sensing line (SL2) and the third sensing line (SL3), measure the voltage of the third battery (Bc) through the third sensing line (SL3) and the fourth sensing line (SL4), and measure the voltage of the fourth battery (Bd) through the fourth sensing line (SL4) and the fifth sensing line (SL5).

[0094] 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 motor of an electric vehicle that receives power from the battery pack (10). As another example, the external device may be a charging device for charging the battery pack (10).

[0095]

[0096] FIG. 6 is a schematic drawing of a vehicle (600) according to another embodiment of the present invention.

[0097] Referring to FIG. 6, a battery pack (610) according to an embodiment of the present invention may be included in a vehicle (600), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (610) may drive the vehicle (600) by supplying power to a motor through an inverter provided in the vehicle (600). Furthermore, the battery pack (610) may include a battery diagnostic device (100) according to an embodiment of the present invention.

[0098]

[0099] FIG. 7 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0100] Preferably, each step of the battery diagnosis method can be performed by the 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.

[0101] The voltage measurement step (S100) is a step of measuring the voltage of multiple batteries, and can be performed by a voltage measurement unit (110).

[0102] For example, the voltage measuring unit (110) can measure the voltage of each of multiple batteries.

[0103] In the embodiment of FIG. 2, the voltage measuring unit (110) can measure the voltages of the first battery (Ba), the second battery (Bb), the third battery (Bc), and the fourth battery (Bd) as Va, Vb, Vc, and Vd.

[0104] The voltage deviation calculation step (S200) is a step for calculating the voltage deviation of multiple batteries, and can be performed by the control unit (120).

[0105] For example, the control unit (120) can calculate the average voltage of multiple batteries. Then, the control unit (120) can calculate the difference between the calculated average voltage and the voltage of each of the multiple batteries, thereby calculating the voltage deviation of each of the multiple batteries.

[0106] In the embodiment of FIG. 2, the control unit (120) can calculate the average voltage of the first battery (Ba), the second battery (Bb), the third battery (Bc), and the fourth battery (Bd) as Vavg. The control unit (120) can calculate the difference between the voltages of the first battery (Ba), the second battery (Bb), the third battery (Bc), and the fourth battery (Bd) and the average voltage, and can calculate the voltage deviations of the first battery (Ba), the second battery (Bb), the third battery (Bc), and the fourth battery (Bd) as dVa, dVb, dVc, and dVd.

[0107] The voltage deviation change amount calculation step (S300) is a step of calculating the voltage deviation change amount of each of a plurality of batteries based on the voltage deviation calculated in the voltage deviation calculation step (S200), and can be performed by the control unit (120).

[0108] In the embodiment of FIG. 3, the control unit (120) can calculate the second voltage deviation change amount as △dV2 according to the formula “dV2-dV1”. The control unit (120) can calculate the third voltage deviation change amount as △dV3 according to the formula “dV3-dV2”. The control unit (120) can calculate the fourth voltage deviation change amount as △dV4 according to the formula “dV4-dV3”.

[0109] In another embodiment, the control unit (120) can calculate the voltage deviation change amount for a unit point in time by dividing the difference in the calculated voltage deviation by the difference in time. For example, in the embodiment of FIG. 3, the control unit (120) can calculate the second voltage deviation change amount for a unit point in time by calculating the formula “second voltage deviation change amount (△dV2) ÷ difference in time (D2-D1)”. The control unit (120) can calculate the third voltage deviation change amount for a unit point in time by calculating the formula “third voltage deviation change amount (△dV3) ÷ difference in time (D3-D2)”. The control unit (120) can calculate the fourth voltage deviation change amount for a unit point in time by calculating the formula “fourth voltage deviation change amount (△dV4) ÷ difference in time (D4-D3)”.

[0110] The comparison step (S400) is a step of comparing the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount, and can be performed by the control unit (120).

[0111] For example, in the embodiment of FIG. 3, the control unit (120) can compare each of the second voltage deviation change amount (△dV2), the third voltage deviation change amount (△dV3), and the fourth voltage deviation change amount (△dV4) with a reference change amount.

[0112] The diagnosis step (S500) is a step of diagnosing the status of each of the plurality of batteries based on the comparison result of the comparison step (S400), and can be performed by the control unit (120).

[0113] The control unit (120) may be configured to diagnose the state of a battery in which the voltage deviation change amount is greater than or equal to a reference change amount as an abnormal state. Conversely, the control unit (120) may be configured to diagnose the state of a battery in which the voltage deviation change amount is less than or equal to a reference change amount as a normal state.

[0114] For example, in the embodiment of FIG. 4, since the second voltage deviation change amount (△dV2) and the third voltage deviation change amount (△dV3) are smaller than the reference change amount (TH), the control unit (120) can diagnose the state of the battery as normal at time points D2 and D3. Since the fourth voltage deviation change amount (△dV4) is larger than the reference change amount (TH), the control unit (120) can diagnose the state of the battery as abnormal at time points D4.

[0115] As another example, the control unit (120) may be configured to calculate the number of times the voltage deviation change amount is greater than a reference change amount, and to diagnose the state of a battery in which the calculated number of times reaches a preset reference number as abnormal.

[0116]

[0117] 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.

[0118] 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.

[0119] 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.

[0120] (Explanation of symbols)

[0121] 10: Battery pack

[0122] 100: Battery Diagnostic Device

[0123] 110: Voltage measurement unit

[0124] 120: Control unit

[0125] 130: Storage

[0126] 600: Car

[0127] 610: Battery Pack

Claims

1. A voltage measuring unit configured to measure the voltage of multiple batteries; and A battery diagnosis device characterized by including a control unit configured to calculate voltage deviations of the plurality of batteries according to the measured plurality of voltages, calculate a voltage deviation change amount of each of the plurality of batteries based on the calculated voltage deviations, compare the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount, and diagnose the status of each of the plurality of batteries based on the comparison result.

2. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the amount of change in voltage deviation of each of the plurality of batteries based on the difference between the voltage deviation calculated at the current point in time and the previous voltage deviation calculated at the previous point in time.

3. In paragraph 2, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the amount of change in voltage deviation by normalizing the difference between the voltage deviation and the previous voltage deviation to the difference between the current point in time and the previous point in time.

4. In paragraph 3, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the difference in voltage deviation by calculating the difference between the voltage deviation and the previous voltage deviation, calculate the difference in time by calculating the difference between the current time and the previous time, and calculate the amount of change in voltage deviation for a unit time by dividing the difference in voltage deviation by the difference in time.

5. In paragraph 1, The above control unit, The above voltage deviation change amount is configured to diagnose the state of the battery as abnormal if it is greater than the reference change amount, A battery diagnosis device characterized in that it is configured to diagnose the state of a battery in which the voltage deviation change amount is less than the reference change amount as a normal state.

6. In paragraph 5, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the number of times the voltage deviation change amount is greater than the reference change amount, and to diagnose the state of a battery in which the calculated number of times reaches a preset reference number as an abnormal state.

7. In paragraph 5, The above control unit, A battery diagnostic device characterized in that it is configured to diagnose that an internal micro-short circuit has occurred in a battery diagnosed as being in the above abnormal state.

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

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

10. Voltage measurement step for measuring the voltage of multiple batteries; A voltage deviation calculation step for calculating voltage deviations of the plurality of batteries based on the plurality of voltages measured in the voltage measurement step; A voltage deviation change amount calculation step for calculating the voltage deviation change amount of each of the plurality of batteries based on the voltage deviation calculated in the voltage deviation calculation step; A comparison step for comparing the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount; and A battery diagnosis method characterized by including a diagnosis step of diagnosing the status of each of the plurality of batteries based on the comparison result of the comparison step.

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