Battery diagnostic device and method

Abstract

A battery diagnostic device according to one embodiment of the present invention includes a voltage measuring unit configured to measure the voltages of a plurality of batteries, and a control unit configured to calculate the voltage deviation of the plurality of batteries based on the measured voltages, calculate the amount of change in voltage deviation for each of the plurality of batteries based on the calculated voltage deviation, compare the amount of change in voltage deviation for each of the plurality of batteries with a preset reference amount of change, and diagnose the state of each of the plurality of batteries according to the result of the comparison.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0098509 filed on July 27, 2023, and all the contents disclosed in the specification and drawings of the said application are incorporated into this application.

[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.

Background Art

[0003] In recent years, with the rapid growth in demand for portable electronic products such as notebook computers, video cameras, and mobile phones, and the full-scale development of electric vehicles, energy storage batteries, robots, artificial satellites, etc., research on high-performance rechargeable batteries has been actively conducted.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries are attracting attention due to their advantages of being almost free from the memory effect compared to nickel-based batteries, being freely chargeable and dischargeable, having a very low self-discharge rate, and a high energy density.

[0005] If a micro short circuit occurs inside the battery, a leakage current of the battery may occur. For example, when a plurality of batteries are included in a battery pack, if an internal micro short circuit occurs in one battery and a leakage current occurs, the voltage of the said battery gradually becomes lower compared to the voltages of other batteries. And if such a phenomenon continues, there is a risk of a hard short circuit occurring and causing permanent damage to the battery pack.

[0006] Therefore, it is necessary to develop a technology for pre-diagnosing whether a micro short circuit has occurred inside the battery. [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention was devised to solve the above-mentioned problems, and aims to provide a battery diagnostic device and method that can diagnose whether or not an internal minute short circuit has occurred in the battery.

[0008] Other objects and advantages of the present invention can be understood from the following description and more clearly from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof shown in the claims. [Means for solving the problem]

[0009] A battery diagnostic device according to one aspect of the present invention includes a voltage measuring unit configured to measure the voltages of a plurality of batteries, and a control unit configured to calculate the voltage deviation of the plurality of batteries based on the measured voltages, calculate the amount of change in voltage deviation for each battery based on the calculated voltage deviation, compare the amount of change in voltage deviation for each battery with a preset reference amount of change, and diagnose the state of each of the plurality of batteries according to the result of the comparison.

[0010] The control unit may be configured to calculate the amount of voltage deviation change for each battery based on the difference between the voltage deviation calculated at the present time and the previous voltage deviation calculated at a previous time.

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

[0012] The control unit may be configured to calculate the difference in voltage deviations 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 at a unit time by dividing the difference in voltage deviations by the difference in time.

[0013] The control unit may be configured to diagnose a battery condition as abnormal if the voltage deviation change amount is greater than or equal to the reference change amount.

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

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

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

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

[0018] An automobile according to yet another aspect of the present invention includes a battery diagnostic device according to one aspect of the present invention.

[0019] A battery diagnostic method according to yet another aspect of the present invention includes: a voltage measurement step of measuring the voltages of a plurality of batteries; a voltage deviation calculation step of calculating the voltage deviation of the plurality of batteries based on the voltages measured in the voltage measurement step; a voltage deviation change amount calculation step of calculating the voltage deviation change amount for each battery based on the voltage deviation calculated in the voltage deviation calculation step; a comparison step of comparing the voltage deviation change amount for each battery with a preset reference change amount; and a diagnostic step of diagnosing the state of each of the plurality of batteries according to the comparison result of the comparison step.

Advantages of the Invention

[0020] According to one aspect of the present invention, the battery diagnostic device can diagnose the state of each of a plurality of batteries by tracking the transition of the amount of change in the voltage deviation of the batteries. Specifically, the battery diagnostic device can quickly diagnose whether there is an internal micro short circuit in each of the plurality of batteries.

[0021] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0022] The drawings attached to this specification serve to make it easier to understand the technical idea of the present invention together with the detailed description of the invention to be described later, and the present invention is not construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram schematically showing a battery diagnostic device according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing the voltages of a plurality of battery cells according to an embodiment of the present invention. [Figure 3] It is a diagram schematically showing the amount of change in voltage deviation according to an embodiment of the present invention. [Figure 4] It is a diagram schematically showing a diagnostic example according to an embodiment of the present invention. [Figure 5] It is a diagram showing an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 6] It is a diagram schematically showing an automobile according to still another embodiment of the present invention. [Figure 7] It is a diagram schematically showing a battery diagnostic method according to still another embodiment of the present invention.

Modes for Carrying Out the Invention

[0024] The terms and words used in this specification and in the claims are not to be interpreted in a manner limited to their general and dictionary meanings, but rather in a manner corresponding to the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best describe their invention.

[0025] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application.

[0026] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such detailed description will be omitted.

[0027] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of several components from others, and these terms do not limit the components themselves.

[0028] When a part of the specification "includes" a certain component, unless otherwise specified, this does not exclude other components, but rather means that it may include other components.

[0029] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only "direct connections" but also "indirect connections" mediated by other elements.

[0030] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0031] Figure 1 is a schematic diagram showing a battery diagnostic device 100 according to one embodiment of the present invention.

[0032] Referring to Figure 1, the battery diagnostic device 100 includes a voltage measuring unit 110 and a control unit 120.

[0033] Here, "battery" refers to a single, independent cell that has a negative terminal and a positive terminal and is physically separable. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. Alternatively, "battery" may refer to a battery module in which multiple cells are connected in series and / or parallel. For the sake of explanation, in the following, "battery" will be described as referring to a single, independent cell.

[0034] The voltage measuring unit 110 may be configured to measure the voltage of multiple batteries.

[0035] Specifically, the voltage measurement unit 110 may be configured to measure the voltage of each of the multiple batteries. Preferably, the voltage measurement unit 110 can measure the open-circuit voltage (OCV) of each of the multiple batteries. For example, the voltage measurement unit 110 can measure the open-circuit voltage of the multiple batteries after a rest period has elapsed following the completion of charging or discharging of the multiple batteries.

[0036] Figure 2 is a schematic diagram showing the voltages of multiple battery cells according to one embodiment of the present invention.

[0037] In the embodiment shown in Figure 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.

[0038] The voltage measurement unit 110 can be connected to the control unit 120 in a communicative manner. For example, the voltage measurement unit 110 and the control unit 120 can be connected by wire and / or wireless. The voltage measurement unit 110 can transmit information about the measured voltage to the control unit 120.

[0039] The control unit 120 may be configured to calculate the voltage deviation of multiple batteries based on the multiple measured voltages.

[0040] Specifically, the control unit 120 can receive voltage information from multiple batteries from the voltage measurement unit 110 and calculate the voltage deviation of the multiple batteries based on the received voltage information.

[0041] First, the control unit 120 may be configured to calculate the average voltage of multiple batteries. In the embodiment shown in Figure 2, the control unit 120 can calculate the average voltage of the voltages from the first battery Ba to the fourth battery Bd. For example, the control unit 120 can calculate the average voltage as Vavg by calculating the formula "(Va + Vb + Vc + Vd) ÷ 4".

[0042] Next, the control unit 120 may be configured to calculate the voltage deviation for each of the batteries by calculating the difference between the calculated average voltage and the voltage of each of the batteries. In the embodiment shown in Figure 2, the control unit 120 can calculate the difference between the voltage of the first battery Ba to the fourth battery Bd and the average voltage, and calculate the voltage deviation from the first battery Ba to the fourth battery Bd. For example, the control unit 120 can calculate the voltage deviation of the first battery Ba as dVa by calculating the formula "|Va-Vavg|", and calculate the voltage deviation of the second battery Bb as dVb by calculating the formula "|Vb-Vavg|". Then, the control unit 120 can calculate the voltage deviation of the third battery Bc as dVc by calculating the formula "|Vc-Vavg|", and calculate the voltage deviation of the fourth battery Bd as dVd by calculating the formula "|Vd-Vavg|". Here, "||" is the symbol for absolute value, and the calculated voltage deviation can be expressed as the absolute value of the difference between the battery voltage and the average voltage.

[0043] The control unit 120 may be configured to calculate the amount of voltage deviation change for each of the multiple batteries based on the calculated voltage deviation.

[0044] Specifically, the control unit 120 may be configured to calculate the voltage deviation change for each of the multiple batteries based on the difference between the voltage deviation calculated at the current time and the previous voltage deviation calculated at a previous time. For example, the control unit 120 may calculate the voltage deviation and the voltage deviation change for each of the multiple batteries each time the voltage of the multiple batteries is measured by the voltage measurement unit 110. Here, if the voltage deviations of the multiple batteries are calculated for the first time, there are no voltage deviations calculated at a previous time, so the calculation of the voltage deviation change may be omitted.

[0045] Figure 3 is a schematic diagram showing the change in voltage deviation according to one embodiment of the present invention. Specifically, the embodiment in Figure 3 shows only the voltage deviation of the first battery Ba among the voltage deviations from the first battery Ba to the fourth battery Bd calculated at times D1, D2, D3, and D4.

[0046] For example, in the embodiment shown in Figure 3, D1, D2, D3, and D4 represent the time when the voltage of the first battery Ba was measured. Specifically, D1, D2, D3, and D4 represent the day 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, the intervals between D1, D2, D3, and D4 are not limited to a predetermined period.

[0047] On the other hand, although Figure 3 only shows the voltage deviation of the first battery Ba, please note that the voltage deviation from the second battery Bb to the fourth battery Bd is also calculated in order to diagnose the condition of the second battery Bb to the fourth battery Bd.

[0048] In the embodiment shown in Figure 3, the first voltage deviation of the first battery Ba calculated at time D1 is dV1, the second voltage deviation of the first battery Ba calculated at time D2 is dV2, the third voltage deviation of the first battery Ba calculated at time D3 is dV3, and the fourth voltage deviation of the first battery Ba calculated at time D4 is dV4. The control unit 120 can calculate the difference between voltage deviations at consecutive time points in order to calculate the change in voltage deviation for the first battery Ba. The control unit 120 can calculate the difference between the voltage deviation at time D1 and the voltage deviation at time D2 using the formula "dV2-dV1" and calculate the change in the second voltage deviation at time D2 as ΔdV2. The control unit 120 can calculate the difference between the voltage deviation at time D2 and the voltage deviation at time D3 using the formula "dV3-dV2" and calculate the change in the third voltage deviation at time D3 as ΔdV3. The control unit 120 can calculate the difference between the voltage deviation at time D4 and the voltage deviation at time D3 using the formula "dV4-dV3", and calculate the fourth voltage deviation change at time D4 as ΔdV4.

[0049] The control unit 120 may be configured to compare the voltage deviation change amount for each of the multiple batteries with a preset reference change amount. The control unit 120 may also be configured to diagnose the state of each of the multiple batteries according to the results of the comparison.

[0050] Here, the reference change can be set considering the characteristics of the battery. Specifically, the reference change can be set considering the battery's form (cylindrical, pouch, and prismatic, etc.), internal configuration (positive electrode material, negative electrode material, separator membrane, and electrolyte, etc.), and specifications. For example, the reference change can be set based on the change in voltage deviation when a small internal short circuit occurs in a reference battery (which is set corresponding to the battery being diagnosed).

[0051] The control unit 120 can compare the magnitude of the voltage deviation change for each of the multiple batteries with a reference change. For example, in the embodiment shown in Figure 3, the control unit 120 can diagnose the state of the battery at time D2 by comparing the second voltage deviation change (ΔdV2) at time D2 with the reference change. The control unit 120 can diagnose the state of the battery at time D3 by comparing the third voltage deviation change (ΔdV3) at time D3 with the reference change. The control unit 120 can diagnose the state of the battery at time D4 by comparing the fourth voltage deviation change (ΔdV4) at time D4 with the reference change.

[0052] Furthermore, the control unit 120 may be configured to diagnose a battery condition as abnormal if the voltage deviation change is greater than or equal to a reference change. Conversely, the control unit 120 may be configured to diagnose a battery condition as normal if the voltage deviation change is less than a reference change.

[0053] Figure 4 is a schematic diagram showing a diagnostic example according to one embodiment of the present invention. Specifically, the embodiment in Figure 4 is a diagnostic example in which the voltage deviation changes (ΔdV2, ΔdV3, ΔdV4) of the first battery according to the embodiment in Figure 3 are compared with a reference change (TH).

[0054] For example, in the embodiment shown in Figure 4, 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 state at time 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 state at time D4 as abnormal.

[0055] A battery diagnostic device 100 according to one embodiment of the present invention can immediately diagnose the state of a battery by taking into account the change in voltage deviation from the previous point in time at each diagnostic point. In other words, the battery diagnostic device 100 can quickly diagnose the state of a battery without taking into account the long-term trend of changes in the state of the battery.

[0056] Furthermore, the battery diagnostic device 100 first determines the relative voltage behavior (voltage deviation) of multiple batteries, and secondarily determines the change in relative voltage behavior (change in voltage deviation) over time for each battery. In other words, the battery diagnostic device 100 diagnoses the state of multiple batteries by considering both the relative voltage behavior of multiple batteries and the change in the voltage behavior of each battery, thereby enabling a more accurate diagnosis of the state of multiple batteries.

[0057] On the other hand, the control unit 120 provided in the battery diagnostic device 100 may selectively include a processor, ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is implemented as software, the control unit 120 may be implemented as a collection of program modules. In this case, the program modules may be recorded in memory and executed by the control unit 120. The memory may be provided inside or outside the control unit 120 and may be connected to the control unit 120 by various well-known means.

[0058] The battery diagnostic device 100 may further include a storage unit 130. The storage unit 130 may store data and programs necessary for each component of the battery diagnostic device 100 to operate and function, or data generated during the process of operation and functioning. The type of storage unit 130 is not particularly limited, as long as it is a known information recording means that is known to be able to record, erase, update, and read data. For example, information recording means may include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, etc. The storage unit 130 may also store program code in which the process that can be executed by the control unit 120 is defined.

[0059] The control unit 120 may be configured to calculate the change in voltage deviation by normalizing the difference between the voltage deviation and the previous voltage deviation relative to the difference between the current time and the previous time.

[0060] Specifically, the control unit 120 can diagnose the state of multiple batteries in conjunction with the voltage measurement unit 110 measuring the voltage of multiple batteries. Here, if the voltage measurement unit 110 measures the voltage aperiodically, the difference between the previous time point and the current time point may not be constant. Also, even if the voltage measurement unit 110 measures the voltage periodically, if the measurement period is too long, the amount of voltage deviation change for each of the multiple batteries may become large. Therefore, the control unit 120 can more accurately diagnose the state of multiple batteries by calculating the amount of voltage deviation change at a unit time point for each of the multiple batteries.

[0061] The control unit 120 may be configured to calculate the difference in voltage deviations by calculating the difference between the voltage deviation and the previous voltage deviation. For example, in the embodiment shown in Figure 3, the control unit 120 may calculate the difference between the first voltage deviation (dV1) and the second voltage deviation (dV2) at time D2 and calculate the change in the second voltage deviation (ΔdV2).

[0062] The control unit 120 may be configured to calculate the time difference by calculating the difference between the current time and a previous time. For example, in the embodiment shown in Figure 3, the control unit 120 may calculate the time difference (dD12) between time D2 and time D1.

[0063] The control unit 120 may be configured to calculate the change in voltage deviation at a given time by dividing the difference in voltage deviations by the difference in time points. For example, in the embodiment shown in Figure 3, the control unit 120 can calculate the change in voltage deviation at a given time point by calculating the formula "change in second voltage deviation (ΔdV2) ÷ difference in time points (D2-D1)". The control unit 120 can calculate the change in third voltage deviation at a given time point by calculating the formula "change in third voltage deviation (ΔdV3) ÷ difference in time points (D3-D2)". The control unit 120 can calculate the change in fourth voltage deviation at a given time point by calculating the formula "change in fourth voltage deviation (ΔdV4) ÷ difference in time points (D4-D3)". If time points D1, D2, D3, and D4 are days, the control unit 120 can calculate the change in voltage deviation on a daily basis.

[0064] The battery diagnostic device 100 diagnoses the battery status based on the voltage deviation change amount at a given time point, thereby reducing the possibility of misdiagnosis of the battery status due to the time difference between a previous time point and the current time point.

[0065] The control unit 120 may be configured to calculate the number of times the voltage deviation change is greater than or equal to a reference change. The control unit 120 may also be configured to diagnose the battery state as abnormal when the calculated number of occurrences reaches a preset reference number.

[0066] Here, the reference count is set to prevent misdiagnosis of the battery condition. For example, the reference count may be set to 3 times. In this case, the control unit 120 can diagnose the battery condition as abnormal if the number of times the voltage deviation change amount is greater than or equal to the reference change amount reaches 3.

[0067] For example, the voltages of multiple batteries may not be accurate due to measurement noise or other factors. If the battery condition is diagnosed based on inaccurate voltages, there is a risk of misdiagnosis. Therefore, in order to prevent misdiagnosis of the battery condition due to unexpected noise or other factors, the battery diagnostic device 100 can diagnose the battery condition by further considering the number of times the voltage deviation change is greater than or equal to a reference change.

[0068] The control unit 120 may be configured to diagnose that an internal minute short circuit has occurred in a battery that has been diagnosed as being in an abnormal state.

[0069] Generally, the occurrence of internal micro-short circuits can be determined by observing the battery's voltage behavior over a long period. In other words, the battery's condition is diagnosed by considering the long-term trend in its voltage. This is because internal micro-short circuits are difficult to immediately confirm through the voltage behavior of a single battery. However, internal micro-short circuits worsen as the battery is used, and severe internal short circuits cause a decrease in battery performance and damage.

[0070] The battery diagnostic device 100 can quickly diagnose the state of batteries without having to check the long-term voltage behavior of each battery, by considering the voltage deviation between multiple batteries and the amount of change in the voltage deviation of each battery. In other words, by quickly diagnosing the state of batteries, the battery diagnostic device 100 can prevent problems such as performance degradation or hard short circuits from occurring in batteries under unexpected circumstances.

[0071] In one embodiment, the control unit 120 can 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). That is, the control unit 120 can electrically isolate an abnormal battery in which a minute internal short circuit has occurred from a normal battery. For example, the control unit 120 can control a switching element or the like corresponding to the abnormal battery to a turn-off state. As another example, the control unit 120 may blow a fuse or the like corresponding to the abnormal battery.

[0072] In other embodiments, the control unit 120 may output information about the abnormal battery to an external device. For example, the control unit 120 may output information about the abnormal battery to an external display device or alarm device. Therefore, users and others can quickly become aware of information about the abnormal battery.

[0073] A battery diagnostic device 100 according to one embodiment of the present invention can be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the battery diagnostic device 100 described above. In such a configuration, at least some of the components of the battery diagnostic device 100 can be realized by complementing or adding to the functions of components included in a conventional BMS. For example, the voltage measurement unit 110, the control unit 120, and the storage unit 130 of the battery diagnostic device 100 can be realized as components of the BMS.

[0074] Furthermore, a battery diagnostic device 100 according to one embodiment of the present invention may be provided in the 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. The battery pack 10 may further include electrical components (relays, fuses, etc.) and a case, etc.

[0075] Figure 5 shows 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.

[0076] 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 shown in Figure 5, the first battery Ba, the second battery Bb, the third battery Bc, and the fourth battery Bd may be connected in series. However, the number of batteries included in the battery pack 10 and the battery connection relationships (series and / or parallel) are not limited by the embodiment shown in Figure 5.

[0077] 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.

[0078] 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.

[0079] 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 to the negative terminal of the first battery Ba through the second sensing line SL2. The voltage measuring unit 110 can measure the voltage of the first battery Ba based on the voltages measured at the first sensing line SL1 and the second sensing line SL2, respectively.

[0080] 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.

[0081] External devices 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. Another example is that the external device may be a charging device for charging the battery pack 10.

[0082] Figure 6 is a schematic diagram showing an automobile 600 according to yet another embodiment of the present invention.

[0083] Referring to Figure 6, the battery pack 610 according to an embodiment of the present invention can be installed in an automobile 600 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 610 can drive the automobile 600 by supplying power to the motor through an inverter provided in the automobile 600. The battery pack 610 may include a battery diagnostic device 100 according to one embodiment of the present invention.

[0084] Figure 7 is a schematic diagram illustrating a battery diagnostic method according to yet another embodiment of the present invention.

[0085] Preferably, each step of the battery diagnostic method can be performed by the battery diagnostic device 100. For the sake of clarity, the following will either omit or briefly explain any content that overlaps with the above explanation.

[0086] The voltage measurement step S100 is a step of measuring the voltage of multiple batteries, which may be performed by the voltage measurement unit 110.

[0087] For example, the voltage measurement unit 110 can measure the voltage of each of the multiple batteries.

[0088] In the embodiment shown in Figure 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.

[0089] The voltage deviation calculation step S200 is a step of calculating the voltage deviation of multiple batteries, which may be performed by the control unit 120.

[0090] 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, and calculate the voltage deviation for each of the multiple batteries.

[0091] In the embodiment shown in Figure 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 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.

[0092] The voltage deviation change calculation step S300 is a step of calculating the voltage deviation change for each of the multiple batteries based on the voltage deviation calculated in the voltage deviation calculation step S200, and can be performed by the control unit 120.

[0093] In the embodiment shown in Figure 3, the control unit 120 can calculate the second voltage deviation change amount as ΔdV2 using the formula "dV2-dV1". The control unit 120 can calculate the third voltage deviation change amount as ΔdV3 using the formula "dV3-dV2". The control unit 120 can calculate the fourth voltage deviation change amount as ΔdV4 using the formula "dV4-dV3".

[0094] In other embodiments, the control unit 120 may calculate the change in voltage deviation at a unit time by dividing the calculated difference in voltage deviations by the difference in time. For example, in the embodiment shown in Figure 3, the control unit 120 may calculate the change in the second voltage deviation at a unit time by calculating the formula "change in second voltage deviation (ΔdV2) ÷ difference in time (D2-D1)". The control unit 120 may calculate the change in the third voltage deviation at a unit time by calculating the formula "change in third voltage deviation (ΔdV3) ÷ difference in time (D3-D2)". The control unit 120 may calculate the change in the fourth voltage deviation at a unit time by calculating the formula "change in fourth voltage deviation (ΔdV4) ÷ difference in time (D4-D3)".

[0095] The comparison step S400 is a step of comparing the voltage deviation change amount for each of the multiple batteries with a preset reference change amount, and can be performed by the control unit 120.

[0096] For example, in the embodiment shown in Figure 3, the control unit 120 can compare the second voltage deviation change (ΔdV2), the third voltage deviation change (ΔdV3), and the fourth voltage deviation change (ΔdV4) with a reference change.

[0097] The diagnostic step S500 is a step in which the state of each of the multiple batteries is diagnosed according to the results of the comparison step S400, and can be performed by the control unit 120.

[0098] The control unit 120 may be configured to diagnose a battery condition as abnormal if the voltage deviation change is greater than or equal to a reference change. Conversely, the control unit 120 may be configured to diagnose a battery condition as normal if the voltage deviation change is less than a reference change.

[0099] For example, in the embodiment shown in Figure 4, 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 state at time 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 state at time D4 as abnormal.

[0100] As another example, the control unit 120 may be configured to calculate the number of times the voltage deviation change is greater than or equal to a reference change, and to diagnose the battery state as abnormal when the calculated number reaches a preset reference number.

[0101] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be implemented through a program that realizes the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such a program is recorded. Such a program or recording medium can be easily implemented by those skilled in the art based on the description of the embodiments described above.

[0102] As described above, the present invention has been explained with limited embodiments and drawings, but it goes without saying that the present invention is not limited thereto, and that various modifications and variations are possible within the equivalent scope of the technical idea and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0103] Furthermore, the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention pertains, without departing from the technical spirit of the invention, and is not limited by the embodiments described above and the accompanying drawings. For diverse modifications, all or part of each embodiment can be selectively combined to form the present invention. [Explanation of symbols]

[0104] 10: Battery Pack 100: Battery diagnostic device 110: Voltage measurement section 120: Control Unit 130: Storage section 600: Automobile 610: Battery Pack

Claims

1. A voltage measuring unit configured to measure the voltage of multiple batteries, A battery diagnostic device comprising: a control unit configured to calculate the voltage deviation of a plurality of batteries based on a plurality of measured voltages, calculate the amount of change in voltage deviation for each battery based on the calculated voltage deviation, compare the amount of change in voltage deviation for each battery with a preset reference amount of change, and diagnose the state of each of the plurality of batteries according to the result of the comparison.

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

3. The control unit, The battery diagnostic device according to claim 2, 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 and the previous time.

4. The control unit, The battery diagnostic device according to claim 3, configured to calculate the difference in voltage deviations 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 at a unit time by dividing the difference in voltage deviations by the difference in time.

5. The control unit, The system is configured to diagnose a battery condition as abnormal if the voltage deviation change amount is greater than or equal to the reference change amount. The battery diagnostic device according to claim 1, configured to diagnose a battery state as normal when the voltage deviation change amount is less than the reference change amount.

6. The control unit, The battery diagnostic device according to claim 5, configured to calculate the number of times the voltage deviation change amount is greater than or equal to the reference change amount, and to diagnose the state of the battery as abnormal when the calculated number of times reaches a preset reference number.

7. The control unit, The battery diagnostic device according to claim 5, which is configured to diagnose that an internal minute short circuit has occurred in the battery diagnosed as being in the aforementioned abnormal state.

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

9. An automobile comprising a battery diagnostic device according to any one of claims 1 to 7.

10. A voltage measurement step to measure the voltage of multiple batteries, A voltage deviation calculation step that calculates the voltage deviation of the plurality of batteries based on the plurality of voltages measured in the voltage measurement step, A voltage deviation change calculation step calculates the amount of voltage deviation change for each battery based on the voltage deviation calculated in the voltage deviation calculation step, A comparison step that compares the voltage deviation change for each battery with a preset reference change, A battery diagnostic method comprising a diagnostic step of diagnosing the state of each of the plurality of batteries according to the results of the comparison step.

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