Battery diagnosis device and battery diagnosis method

Abstract

A battery diagnosis device according to one embodiment of the present disclosure comprises: a voltage measurement unit for measuring voltages of a plurality of batteries; and a control unit that calculates a voltage deviation of the plurality of batteries from the measured plurality of voltages, calculates a voltage deviation change amount of each of the plurality of batteries based on the calculated voltage deviation, compares the voltage deviation change amount of each of the plurality of batteries with a preset reference change amount, and calculates a voltage deviation of each of the plurality of batteries based on the calculated voltage deviation. And diagnosing a state of each of the plurality of batteries according to a comparison result.

Description

Technical Field

[0001] This application claims priority from Korean Patent Application No. 10-2023-0098509 filed in Korea on Jul. 27, 2023, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a battery diagnostic device and a battery diagnostic method, and in particular to a battery diagnostic device and a battery diagnostic method capable of diagnosing micro short circuits inside a battery. Background Art

[0003] Recently, the demand for portable electronic products such as laptop computers, video cameras, and mobile phones has increased dramatically, and the development of electric vehicles, energy storage batteries, robots, satellites, etc. has continued to advance. Therefore, research is actively underway on high-performance batteries that allow repeated charging and discharging.

[0004] Currently commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these batteries, lithium batteries have attracted widespread attention because they have almost no memory effect compared to nickel-based batteries, and have a very low self-discharge rate and high energy density.

[0005] If a micro-short occurs within a battery, leakage current may occur. For example, consider a battery pack containing multiple batteries. If a micro-short occurs within one battery and leakage current occurs, the voltage of that battery may gradually decrease compared to the voltages of the other batteries. Furthermore, if this phenomenon continues, a hard short circuit may occur, potentially causing permanent damage to the battery pack.

[0006] Therefore, it is necessary to develop a technology that can pre-diagnose whether a micro short circuit occurs inside the battery. Summary of the Invention

[0007] Technical issues

[0008] The present disclosure aims to solve the problems existing in the prior art, and thus the present disclosure aims to provide a battery diagnosis device and method for diagnosing whether an internal micro short circuit occurs in a battery.

[0009] These and other purposes and advantages of the present disclosure can be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Moreover, it will be readily understood that the purposes and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0010] Technical Solution

[0011] According to one aspect of the present disclosure, a battery diagnostic device may include: a voltage measuring unit, which is configured to measure the voltages of a plurality of batteries; a control unit, which is configured to calculate voltage deviations of the plurality of batteries based on the measured plurality of voltages, calculate a voltage deviation change of each of the plurality of batteries based on the calculated voltage deviations, compare the voltage deviation change of each of the plurality of batteries with a preset reference change, and diagnose a state of each of the plurality of batteries based on the comparison result.

[0012] The control unit may be configured to calculate the voltage deviation change amount of each of the plurality of batteries based on a difference between the voltage deviation calculated at a current time point and a previous voltage deviation calculated at a previous time point.

[0013] The control unit may be configured to calculate the voltage deviation change amount by normalizing a difference between the voltage deviation and the previous voltage deviation with respect to a difference between the current time point and the previous time point.

[0014] The control unit may be configured to calculate the voltage deviation difference by calculating the difference between the voltage deviation and the previous voltage deviation, calculate the time point difference by calculating the difference between the current time point and the previous time point, and calculate the voltage deviation change amount per unit time point by dividing the voltage deviation difference by the time point difference.

[0015] The control unit may be configured to diagnose a battery state in which the voltage deviation variation is greater than or equal to the reference variation as an abnormal state.

[0016] The control unit may be configured to diagnose a battery state in which the voltage deviation variation is smaller than the reference variation as a normal state.

[0017] The control unit may be configured to count the number of times the voltage deviation variation is greater than or equal to the reference variation, and diagnose a battery state when the counted number of times reaches a preset reference number of times as an abnormal state.

[0018] The control unit may be configured to diagnose that an internal micro short circuit occurs in the battery diagnosed as the abnormal state.

[0019] A battery pack according to another aspect of the present disclosure may include the battery diagnostic device according to one aspect of the present disclosure.

[0020] A vehicle according to still another aspect of the present disclosure may include the battery diagnostic apparatus according to one aspect of the present disclosure.

[0021] According to another aspect of the present disclosure, a battery diagnosis method may include: a voltage measuring step, wherein the voltage measuring step measures the voltages of a plurality of batteries; a voltage deviation calculating step, wherein the voltage deviation calculating step calculates the voltage deviations of the plurality of batteries based on the plurality of voltages measured in the voltage measuring step; a voltage deviation change calculating step, wherein the voltage deviation change calculating step calculates the voltage deviation change of each of the plurality of batteries based on the voltage deviation calculated in the voltage deviation calculating step; a comparison step, wherein the voltage deviation change of each of the plurality of batteries is compared with a preset reference change; and a diagnosis step, wherein the diagnosis step diagnoses the state of each of the plurality of batteries based on the comparison result of the comparison step.

[0022] Beneficial effects

[0023] According to one aspect of the present disclosure, a battery diagnostic device can diagnose the status of each of a plurality of batteries by tracking the trend of the battery voltage deviation change. Specifically, the battery diagnostic device can quickly diagnose whether an internal micro short circuit occurs in each of the plurality of batteries.

[0024] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings illustrate preferred embodiments of the present disclosure and are used to provide further understanding of the technical features of the present disclosure together with the foregoing disclosure. Therefore, the present disclosure should not be construed as being limited to the accompanying drawings.

[0026] Figure 1 FIG. 1 is a diagram schematically illustrating a battery diagnosis device according to the present disclosure.

[0027] Figure 2 is a schematic diagram illustrating voltages of a plurality of battery cells according to an embodiment of the present disclosure.

[0028] Figure 3 FIG. 2 is a schematic diagram illustrating a voltage deviation variation according to an embodiment of the present disclosure.

[0029] Figure 4 is a schematic diagram illustrating a diagnosis embodiment according to an embodiment of the present disclosure.

[0030] Figure 5 is a diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0031] Figure 6 is a diagram schematically illustrating a vehicle according to yet another embodiment of the present disclosure.

[0032] Figure 7 FIG. 2 is a diagram schematically illustrating a battery diagnosis method according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concepts corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms for best interpretation.

[0034] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes, and are not intended to limit the scope of the present disclosure, and it should be understood that other equivalents and modifications may be made to the descriptions without departing from the scope of the present disclosure.

[0035] Additionally, in describing the present disclosure, when a detailed description of related known elements or functions is deemed to make the key subject matter of the present disclosure unclear, the detailed description will be omitted herein.

[0036] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from another among various elements, but are not intended to limit the elements by the terms.

[0037] Throughout the specification, when a part is referred to as “comprising” or “including” any elements, it means that the part may further include other elements, without excluding other elements, unless specifically stated otherwise.

[0038] Furthermore, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0039] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0040] Figure 1 FIG. 1 is a diagram schematically illustrating a battery diagnosis device 100 according to an embodiment of the present disclosure.

[0041] Reference Figure 1 The battery diagnosis device 100 may include a voltage measuring unit 110 and a control unit 120 .

[0042] Here, a battery refers to a physically separable individual cell with a negative terminal and a positive terminal. For example, a lithium-ion cell or a lithium-polymer cell can be considered a battery. Furthermore, a battery can also refer to a battery module having multiple cells connected in series and / or parallel. For ease of explanation, a battery will be described below as referring to a single individual cell.

[0043] The voltage measuring unit 110 may be configured to measure voltages of a plurality of batteries.

[0044] 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, when charging or discharging of the plurality of batteries is completed and a rest period has elapsed, the voltage measuring unit 110 may measure the open circuit voltage of the plurality of batteries.

[0045] Figure 2 is a schematic diagram illustrating voltages of a plurality of battery cells according to an embodiment of the present disclosure.

[0046] exist Figure 2 In the embodiment of FIG. 1 , 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 may 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.

[0047] In addition, the voltage measuring unit 110 may be connected to communicate with the control unit 120. For example, the voltage measuring unit 110 and the control unit 120 may be connected by wire and / or wirelessly. The voltage measuring unit 110 may transmit information related to the measured voltage to the control unit 120.

[0048] The control unit 120 may be configured to calculate voltage deviations of the plurality of batteries based on the measured plurality of voltages.

[0049] Specifically, the control unit 120 may receive voltage information of the plurality of batteries from the voltage measurement unit 110 and calculate voltage deviations of the plurality of batteries based on the received voltage information.

[0050] First, the control unit 120 may be configured to calculate the average voltage of the plurality of batteries. Figure 2 In the embodiment, the control unit 120 may calculate the average voltage of the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd. For example, the control unit 120 may calculate the average voltage Vavg using the formula “(Va+Vb+Vc+Vd)÷4”.

[0051] Next, the control unit 120 may be configured to calculate a difference between the calculated average voltage and the voltage of each of the plurality of batteries to calculate a voltage deviation of each of the plurality of batteries. Figure 2In this embodiment, the control unit 120 can calculate the difference between the voltage of the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd and the average voltage to calculate the voltage deviation of the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd. For example, the control unit 120 can calculate the voltage deviation dVa of the first battery Ba using the calculation formula "|Va-Vavg|" and the voltage deviation dVb of the second battery Bb using the calculation formula "|Vb-Vavg|". In addition, the control unit 120 can calculate the voltage deviation dVc of the third battery Bc using the calculation formula "|Vc-Vavg|" and the voltage deviation dVd of the fourth battery Bd using the calculation formula "|Vd-Vavg|". Here, "||" represents an absolute value symbol, and the calculated voltage deviation can be expressed as the absolute value of the difference between the battery voltage and the average voltage.

[0052] The control unit 120 may be configured to calculate a voltage deviation change amount of each of the plurality of batteries based on the calculated voltage deviation.

[0053] Specifically, the control unit 120 may be configured to calculate the voltage deviation change for each of the plurality of batteries based on the difference between the voltage deviation calculated at the current time point and the previous voltage deviation calculated at the previous time point. For example, each time the voltage of the plurality of batteries is measured by the measurement unit 110, the control unit 120 may calculate the voltage deviation and the voltage deviation change for each of the plurality of batteries. When the voltage deviations of the plurality of batteries are first calculated, there are no voltage deviations calculated at the previous time point, and thus the calculation of the voltage deviation change may be omitted.

[0054] Figure 3 is a schematic diagram showing the voltage deviation variation according to an embodiment of the present disclosure. Specifically, Figure 3 The embodiment is a graph showing only the voltage deviation of the first battery Ba among the voltage deviations of the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd calculated at the time points D1, D2, D3, and D4.

[0055] For example, in Figure 3 In the embodiment, D1, D2, D3, and D4 represent the time points at which the voltage of the first battery Ba is measured. Specifically, D1, D2, D3, and D4 represent the dates on which the voltage of the first battery Ba is measured. Here, the intervals between D1, D2, D3, and D4 can be the same or different. That is, it should be noted that the intervals between D1, D2, D3, and D4 are not limited to predetermined periods.

[0056] In addition, although Figure 3Only the voltage deviation of the first battery Ba is shown, but it should be noted that the voltage deviations of the second battery Bb, third battery Bc, and fourth battery Bd are also calculated for status diagnosis of the second battery Bb, third battery Bc, and fourth battery Bd.

[0057] exist Figure 3 In the embodiment, 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 between the voltage deviations at consecutive time points to calculate the voltage deviation change of the first battery Ba. The control unit 120 can calculate the difference between the voltage deviation at time point D1 and the voltage deviation at time point D2 according to the formula "dV2-dV1" to calculate the second voltage deviation change ΔdV2 corresponding to time point D2. The control unit 120 can calculate the difference between the voltage deviation at time point D2 and the voltage deviation at time point D3 according to the formula "dV3-dV2" to calculate the third voltage deviation change ΔdV3 corresponding to time point D3. The control unit 120 may calculate the difference between the voltage deviation at time point D4 and the voltage deviation at time point D3 according to the formula “dV4−dV3” to calculate a fourth voltage deviation change ΔdV4 corresponding to time point D4.

[0058] The control unit 120 may be configured to compare the voltage deviation variation of each of the plurality of batteries with a preset reference variation. In addition, the control unit 120 may be configured to diagnose the state of each of the plurality of batteries based on the comparison result.

[0059] Here, the reference variation can be set based on the characteristics of the battery. Specifically, the reference variation can be set based on the battery's shape (cylindrical, pouch, prismatic, etc.), internal materials (positive electrode material, negative electrode material, separator, electrolyte, etc.), and specifications. For example, the reference variation can be set based on the voltage deviation variation when an internal micro-short circuit occurs in a reference battery (set to correspond to the battery to be diagnosed).

[0060] The control unit 120 may compare the magnitude of the voltage deviation variation of each battery in the plurality of batteries with a reference variation. Figure 3In the embodiment of the present invention, the control unit 120 can diagnose the battery status at time point D2 by comparing the second voltage deviation change ΔdV2 at time point D2 with the reference change. The control unit 120 can diagnose the battery status at time point D3 by comparing the third voltage deviation change ΔdV3 at time point D3 with the reference change. The control unit 120 can diagnose the battery status at time point D4 by comparing the fourth voltage deviation change ΔdV4 at time point D4 with the reference change.

[0061] Furthermore, the control unit 120 may be configured to diagnose a battery state in which the voltage deviation variation is greater than or equal to a reference variation as an abnormal state. Conversely, the control unit 120 may be configured to diagnose a battery state in which the voltage deviation variation is less than the reference variation as a normal state.

[0062] Figure 4 is a schematic diagram illustrating a diagnosis embodiment according to an embodiment of the present disclosure. Specifically, Figure 4 The embodiment is to Figure 3 An embodiment of the embodiment in which the voltage deviation variation amounts ΔdV2, ΔdV3, and ΔdV4 of the first battery are compared with the reference variation amount TH.

[0063] For example, in Figure 4 In the embodiment, since the second voltage deviation variation ΔdV2 and the third voltage deviation variation ΔdV3 are smaller than the reference variation TH, the control unit 120 can diagnose the battery status at time points D2 and D3 as normal. Since the fourth voltage deviation variation ΔdV4 is larger than the reference variation TH, the control unit 120 can diagnose the battery status at time point D4 as abnormal.

[0064] The advantage of the battery diagnostic device 100 according to an embodiment of the present disclosure is that it can immediately diagnose the battery's condition by considering the amount of change in voltage deviation at each diagnostic time point compared to the previous time point. In other words, the advantage of the battery diagnostic device 100 is that it can quickly diagnose the battery's condition even without considering the long-term trend of battery condition changes.

[0065] Furthermore, battery diagnostic device 100 first determines the relative voltage behavior (voltage deviation) of the multiple batteries, and secondly determines the temporal change in the relative voltage behavior (voltage deviation variation) of each battery. In other words, because battery diagnostic device 100 diagnoses the status of the multiple batteries by considering both the relative voltage behavior of the multiple batteries and the change in the voltage behavior of each battery, it offers the advantage of being able to more accurately diagnose the status of the multiple batteries.

[0066] In addition, the control unit 120 included in the battery diagnostic device 100 may optionally include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing equipment, etc., as known in the art, to execute the various control logics performed in the present disclosure. In addition, when the control logic is implemented as 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 internal or external to the control unit 120 and may be connected to the control unit 120 via various well-known means.

[0067] The battery diagnostic device 100 may also include a storage unit 130. The storage unit 130 can store data required for the operation and function of each component of the battery diagnostic device 100, as well as data generated during the execution of such operations or functions. The type of storage unit 130 is not particularly limited, as long as it is a known information storage device capable of recording, erasing, updating, and reading data. Examples of information storage devices include RAM, flash memory, ROM, EEPROM, registers, and the like. Furthermore, the storage unit 130 may store program code that defines the processes executable by the control unit 120.

[0068] The control unit 120 may be configured to calculate the voltage deviation change amount by normalizing the difference between the voltage deviation and the previous voltage deviation with respect to the difference between the current time point and the previous time point.

[0069] Specifically, the control unit 120 can diagnose the status of the multiple batteries based on the time points at which the measurement unit 110 measures the voltages of the multiple batteries. Here, if the measurement unit 110 measures the voltage non-periodically, 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 period is too long, the voltage deviation change of each of the multiple batteries will inevitably increase. Therefore, the control unit 120 can more accurately diagnose the status of the multiple batteries by calculating the voltage deviation change of each of the multiple batteries per unit time point.

[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. Figure 3 In the embodiment of FIG. 5 , the control unit 120 may calculate the second voltage deviation variation ΔdV2 by calculating the difference between the first voltage deviation dV1 and the second voltage deviation dV2 at the time point D2 .

[0071] The control unit 120 may be configured to calculate the difference in time points by calculating the difference between the current time point and the previous time point. Figure 3 In the embodiment, the control unit 120 may calculate a time point difference dD12 between the time point D2 and the time point D1.

[0072] The control unit 120 may be configured to calculate the voltage deviation variation per unit time point by dividing the voltage deviation difference by the time point difference. Figure 3 In the embodiment, the control unit 120 can calculate the second voltage deviation change per unit time point by calculating the formula "second voltage deviation change ΔdV2 ÷ time point difference (D2-D1)". The control unit 120 can calculate the third voltage deviation change per unit time point by calculating the formula "third voltage deviation change ΔdV3 ÷ time point difference (D3-D2)". The control unit 120 can calculate the fourth voltage deviation change per unit time point by calculating the formula "fourth voltage deviation change ΔdV4 ÷ time point difference (D4-D3)". If the time points D1, D2, D3 and D4 are time points of a day, the control unit 120 can calculate the daily voltage deviation change.

[0073] Since the battery diagnosis apparatus 100 diagnoses the battery status based on the voltage deviation variation per unit time point, the possibility of misdiagnosis of the battery status due to the time point difference between the previous time point and the current time point can be reduced.

[0074] The control unit 120 may be configured to count the number of times the voltage deviation variation is greater than or equal to a reference variation. In addition, the control unit 120 may be configured to diagnose the battery state as abnormal when the counted number reaches a preset reference number.

[0075] Here, a reference number of times is set to prevent the battery status from being misdiagnosed. For example, the reference number of times can be set to 3. In this case, if the voltage deviation change is greater than or equal to the reference change for 3 times, the control unit 120 can diagnose the battery status as abnormal.

[0076] 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 concern that the battery status may be misdiagnosed. Therefore, battery diagnostic apparatus 100 can further consider the number of times the voltage deviation variation is greater than or equal to a reference variation when diagnosing the battery status, thereby preventing the battery status from being misdiagnosed due to unexpected noise, etc.

[0077] The control unit 120 may be configured to diagnose that an internal micro short circuit occurs in the battery diagnosed as being in an abnormal state.

[0078] Typically, the occurrence of an internal micro-short circuit can be determined by observing the battery's voltage behavior over a long period of time. In other words, the battery's condition can be diagnosed by considering the long-term trend of the battery's voltage. This is because internal micro-short circuits are difficult to immediately identify based on the voltage behavior of a single cell. However, internal micro-short circuits worsen with battery use, and worsening internal short circuits can lead to performance degradation and battery damage.

[0079] The battery diagnostic device 100 has the advantage of being able to quickly diagnose the battery's condition by considering the voltage deviations between multiple batteries and the amount of change in the voltage deviation for each battery, without having to examine the long-term voltage behavior of each battery. In other words, the battery diagnostic device 100 has the advantage of being able to prevent problems such as battery performance degradation or hard short circuits from occurring unexpectedly by quickly diagnosing the battery's condition.

[0080] In one embodiment, the control unit 120 may disconnect the electrical connection between a battery diagnosed as abnormal (hereinafter referred to as an "abnormal battery") and a battery diagnosed as normal (hereinafter referred to as a "normal battery"). In other words, the control unit 120 may electrically isolate the abnormal battery experiencing a micro-internal short circuit from the normal batteries. For example, the control unit 120 may control a switch element or the like corresponding to the abnormal battery to be in an off state. As another example, the control unit 120 may blow a fuse corresponding to the abnormal battery.

[0081] In another embodiment, the control unit 120 may output information about the abnormal battery to the outside. For example, the control unit 120 may output the information about the abnormal battery to an external display device or an alarm device. Thus, the user or the like can quickly access the information about the abnormal battery.

[0082] The battery diagnostic device 100 according to the present disclosure can be applied to a battery management system (BMS). That is, the BMS according to the present disclosure can include the battery diagnostic device 100 described above. In this configuration, at least some components of the battery diagnostic device 100 can be implemented by supplementing or adding the functions of components included in a conventional BMS. For example, the voltage measurement unit 110, control unit 120, and storage unit 130 of the battery diagnostic device 100 can be implemented as components of the BMS.

[0083] Furthermore, the battery diagnostic device 100 according to the present disclosure may be provided in a battery pack 10. That is, the battery pack 10 according to the present disclosure may include the battery diagnostic device 100 and at least one battery cell. Furthermore, the battery pack 10 may further include electrical components (relays, fuses, etc.) and a housing.

[0084] Figure 51 is a diagram illustrating an exemplary configuration of a battery pack 10 according to another embodiment of the present disclosure. Preferably, the battery pack 10 may include a battery diagnosis device 100.

[0085] The battery pack 10 may include a first battery Ba, a second battery Bb, a third battery Bc, and a fourth battery Bd. Figure 5 In the embodiment of FIG. 1 , 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 of the batteries (series and / or parallel) are not affected by Figure 5 The limitations of the embodiments.

[0086] The positive terminal of the first battery Ba may be connected to the positive terminal P+ of the battery pack 10 , and the negative terminal of the fourth battery Bd may be connected to the negative terminal P− of the battery pack 10 .

[0087] The voltage measuring unit 110 may be connected to a first sensing line SL1 , a second sensing line SL2 , a third sensing line SL3 , a fourth sensing line SL4 , and a fifth sensing line SL5 .

[0088] 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 from each of the first sensing line SL1 and the second sensing line SL2.

[0089] Similarly, 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.

[0090] An external device may be connected to the positive terminal P+ and the 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.

[0091] Figure 6 is a diagram schematically illustrating a vehicle 600 according to yet another embodiment of the present disclosure.

[0092] refer to Figure 6The battery pack 610 according to an embodiment of the present disclosure may be included in a vehicle 600 such as an electric vehicle (EV) or a hybrid vehicle (HV). In addition, the battery pack 610 may power a motor through an inverter provided in the vehicle 600 to drive the vehicle 600.

[0093] Figure 7 FIG. 2 is a diagram schematically illustrating a battery diagnosis method according to yet another embodiment of the present disclosure.

[0094] Preferably, each step of the battery diagnosis method can be performed by the battery diagnosis apparatus 100. Hereinafter, for the convenience of explanation, the contents repeated with the previously described contents will be briefly described or omitted.

[0095] The voltage measuring step S100 is a step of measuring voltages of a plurality of batteries and may be performed by the voltage measuring unit 110 .

[0096] For example, the voltage measuring unit 110 may measure the voltage of each of the plurality of batteries.

[0097] exist Figure 2 In the embodiment of FIG. 5 , the voltage measuring unit 110 may 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.

[0098] The voltage deviation calculating step S200 is a step for calculating voltage deviations of a plurality of batteries and may be performed by the control unit 120 .

[0099] For example, the control unit 120 may calculate an average voltage of the plurality of batteries. Then, the control unit 120 may calculate a voltage deviation of each of the plurality of batteries by calculating a difference between the calculated average voltage and the voltage of each of the plurality of batteries.

[0100] exist Figure 2 In the embodiment of FIG. 1 , the control unit 120 may 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 may calculate the difference between the voltage of the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd and the average voltage to 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.

[0101] The voltage deviation change amount calculation step S300 is a step of calculating a voltage deviation change amount of each of the plurality of batteries based on the voltage deviation calculated in the voltage deviation calculation step S200 , and may be performed by the control unit 120 .

[0102] exist Figure 3In the embodiment, the control unit 120 may calculate the second voltage deviation change as ΔdV2 according to the formula "dV2-dV1". The control unit 120 may calculate the third voltage deviation change as ΔdV3 according to the formula "dV3-dV2". The control unit 120 may calculate the fourth voltage deviation change as ΔdV4 according to the formula "dV4-dV3".

[0103] In another embodiment, the control unit 120 can calculate the voltage deviation change per unit time point by dividing the calculated voltage deviation difference by the time point difference. Figure 3 In the embodiment, the control unit 120 can calculate the second voltage deviation change per unit time point by using the calculation formula "second voltage deviation change ΔdV2 ÷ time point difference (D2-D1)". The control unit 120 can calculate the third voltage deviation change per unit time point by using the calculation formula "third voltage deviation change ΔdV3 ÷ time point difference (D3-D2)". The control unit 120 can calculate the fourth voltage deviation change per unit time point by using the calculation formula "fourth voltage deviation change ΔdV4 ÷ time point difference (D4-D3)".

[0104] The comparison step S400 is a step of comparing the voltage deviation variation of each of the plurality of batteries with a preset reference variation, and may be performed by the control unit 120 .

[0105] For example, in Figure 3 In the embodiment of FIG. 5 , the control unit 120 may compare each of the second voltage deviation variation ΔDv2 , the third voltage deviation variation ΔdV3 , and the fourth voltage deviation variation ΔdV4 with a reference variation.

[0106] The diagnosis step S500 is a step of diagnosing a state of each of the plurality of batteries according to the comparison result of the comparison step S400 , and may be performed by the control unit 120 .

[0107] The control unit 120 may be configured to diagnose a battery state in which the voltage deviation variation is greater than or equal to a reference variation as an abnormal state. Conversely, the control unit 120 may be configured to diagnose a battery state in which the voltage deviation variation is less than the reference variation as a normal state.

[0108] For example, in Figure 4 In the embodiment, since the second voltage deviation change ΔdV2 and the third voltage deviation change ΔdV3 are smaller than the reference change TH, the control unit 120 can diagnose the battery status at time points D2 and D3 as normal. Since the fourth voltage deviation change ΔdV4 is larger than the reference change TH, the control unit 120 can diagnose the battery status at time point D4 as abnormal.

[0109] As another example, the control unit 120 may be configured to count the number of times the voltage deviation variation is greater than or equal to a reference variation, and diagnose the battery state as an abnormal state when the counted number reaches a preset reference number.

[0110] The embodiments of the present disclosure described above can be implemented not only by devices and methods, but also by programs that implement functions corresponding to the configurations of the embodiments of the present disclosure or recording media that record the programs. Those skilled in the art can easily implement the programs or recording media from the description of the above embodiments.

[0111] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0112] In addition, without departing from the technical aspects of the present disclosure, those skilled in the art may make many substitutions, modifications and changes to the present disclosure described above, and the present disclosure is not limited to the above-mentioned embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

[0113] (Explanation of Reference Numerals)

[0114] 10: Battery pack

[0115] 100: Battery diagnostic device

[0116] 110: Voltage measurement unit

[0117] 120: Control unit

[0118] 130: Storage unit

[0119] 600: Vehicle

[0120] 610: Battery Pack

Claims

1. A battery diagnostic device, comprising: a voltage measuring unit configured to measure voltages of the plurality of batteries; a control unit configured to calculate voltage deviations of the plurality of batteries based on 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 a state of each of the plurality of batteries based on a comparison result.

2. The battery diagnostic device according to claim 1, in, The control unit is configured to calculate the voltage deviation change amount of each of the plurality of batteries based on a difference between a voltage deviation calculated at a current time point and a previous voltage deviation calculated at a previous time point.

3. The battery diagnostic device according to claim 2, in, The control unit is configured to calculate the voltage deviation change amount by normalizing a difference between the voltage deviation and the previous voltage deviation with respect to a difference between the current time point and the previous time point.

4. The battery diagnostic device according to claim 3, in, The control unit is configured to calculate the voltage deviation difference by calculating the difference between the voltage deviation and the previous voltage deviation, calculate the time point difference by calculating the difference between the current time point and the previous time point, and calculate the voltage deviation change amount per unit time point by dividing the voltage deviation difference by the time point difference.

5. The battery diagnostic device according to claim 1, in, The control unit is configured to diagnose a battery state in which the voltage deviation variation is greater than or equal to the reference variation as an abnormal state, and The control unit is configured to diagnose a battery state in which the voltage deviation change is smaller than the reference change as a normal state.

6. The battery diagnostic device according to claim 5, in, The control unit is configured to count the number of times the voltage deviation variation is greater than or equal to the reference variation, and diagnose a battery state when the counted number of times reaches a preset reference number of times as an abnormal state.

7. The battery diagnostic device according to claim 5, in, The control unit is configured to diagnose that an internal micro short circuit occurs in the battery diagnosed as being in the abnormal state. 8 . A battery pack comprising the battery diagnostic device according to claim 1 . 9 . A vehicle comprising the battery diagnosis device according to claim 1 .

10. A battery diagnosis method, comprising: a voltage measuring step of measuring the voltages of the plurality of batteries; a voltage deviation calculating 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 amount calculating step of calculating a voltage deviation change amount of each of the plurality of batteries based on the voltage deviation calculated in the voltage deviation calculating step; a comparing step of comparing the voltage deviation variation of each battery in the plurality of batteries with a preset reference variation; as well as a diagnosing step of diagnosing a state of each of the plurality of batteries based on the comparison result of the comparing step.

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