Battery diagnostic device and method, and battery pack including the same

Abstract

A battery diagnosis device according to an embodiment of the present application includes a voltage measurement unit configured to measure a voltage of each of a plurality of battery cells included in a battery module at each voltage measurement interval, and a control unit configured to obtain voltage values of the plurality of battery cells from the voltage measurement unit at each voltage measurement interval, calculate voltage variations between the obtained voltage values of the plurality of battery cells, calculate a voltage variation rate between the calculated plurality of voltage variation amounts at a diagnosis interval different from the voltage measurement interval, and diagnose the battery module based on a preset standard variation rate and one or more voltage variation rates calculated.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0184947, filed in Korea on December 28, 2020, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery diagnostic apparatus and method, and more specifically, to a battery diagnostic apparatus and method capable of diagnosing the state of a battery module based on the voltage behavior of a plurality of battery cells included in a battery module. Background Technology

[0003] In recent years, the demand for portable electronic products such as laptops, cameras, and mobile phones has increased dramatically, and electric vehicles, energy storage batteries, robots, and satellites have seen vigorous development. Therefore, research is actively underway on high-performance batteries that allow for repeated charging and discharging.

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have attracted much attention due to their almost non-existent memory effect, extremely low self-charging rate, and high energy density compared to nickel-based batteries.

[0005] Traditionally, battery condition is diagnosed by considering changes in voltage, temperature, and current. Specifically, the presence of overvoltage and / or undervoltage is monitored based on a comparison of the battery voltage with a standard value.

[0006] However, traditionally, since the state of a battery is diagnosed based on its voltage at a specific point in time, it is impossible to grasp the voltage fluctuation trend of the battery, making it difficult to diagnose the battery's state based on the voltage fluctuation trend. Summary of the Invention

[0007] Technical issues

[0008] This disclosure aims to address the problems in the related technologies, and therefore aims to provide a battery diagnostic device and method that can diagnose the state of a battery module based on the voltage fluctuation trends of multiple battery cells.

[0009] These and other objects and advantages of this disclosure may be understood from the following detailed description and will become more apparent from the exemplary embodiments of this disclosure. Furthermore, it will be readily understood that the objects and advantages of this disclosure may be achieved by the manner shown in the appended claims and combinations thereof.

[0010] Technical solution

[0011] A battery diagnostic apparatus according to one aspect of this disclosure may include: a voltage measurement unit configured to measure the voltage of each of a plurality of battery cells included in a battery module in each voltage measurement cycle; and a control unit configured to obtain voltage values ​​of the plurality of battery cells from the voltage measurement unit in each voltage measurement cycle, calculate voltage change amounts between a plurality of voltage values ​​of the plurality of battery cells obtained, calculate voltage change rates between a plurality of calculated voltage change amounts in each diagnostic cycle different from the voltage measurement cycle, and diagnose the battery module based on one or more voltage change rates calculated up to the current diagnostic cycle and a preset standard change rate.

[0012] The control unit can be configured to compare the voltage change rate calculated in the current diagnostic cycle with the standard change rate, and diagnose the state of the battery module based on the comparison result.

[0013] The control unit can be configured to diagnose the battery module based on the voltage change rate and a reference change rate preset in a previous diagnostic cycle when the voltage change rate is equal to or greater than the standard change rate.

[0014] The control unit can be configured to diagnose the battery module as a normal module when the voltage change rate is less than the standard change rate.

[0015] The control unit can be configured to preset the maximum voltage change rate among one or more voltage change rates calculated in a previous diagnostic cycle as the reference change rate.

[0016] The control unit can be configured to diagnose the battery module as a defective module when the voltage change rate is equal to or greater than the standard change rate and the reference change rate.

[0017] The control unit can be configured to diagnose the battery module as a normal module when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate.

[0018] The control unit can be configured to determine the state of the battery module in each diagnostic cycle based on at least one of the voltage change rate, the standard change rate, and the reference change rate, adjust a pre-designed value according to the determined state of the battery module, and diagnose the battery module based on the adjusted count value and the preset standard value.

[0019] The control unit can be configured to diagnose the battery module as a defective module when the adjusted count value is equal to or greater than the standard value.

[0020] The control unit can be configured to decrease the count value when the voltage change rate is less than the standard change rate.

[0021] The control unit can be configured to decrease the count value when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate.

[0022] The control unit can be configured to increment the count value when the voltage change rate is equal to or greater than the standard change rate and the reference change rate.

[0023] The diagnostic cycle can be set to be longer than the voltage measurement cycle.

[0024] According to another aspect of this disclosure, a battery pack may include a battery diagnostic device according to another aspect of this disclosure.

[0025] A battery diagnostic method according to another aspect of this disclosure may include: a voltage measurement step, measuring the voltage of each of a plurality of battery cells included in a battery module in each voltage measurement cycle; a voltage change calculation step, calculating the voltage change between a plurality of voltage values ​​of the plurality of battery cells in each voltage measurement cycle; a voltage change rate calculation step, calculating the voltage change rate between a plurality of calculated voltage changes in each diagnostic cycle different from the voltage measurement cycle; and a battery module diagnostic step, diagnosing the battery module based on one or more voltage change rates calculated up to the current diagnostic cycle and a preset standard change rate.

[0026] Beneficial effects

[0027] According to one aspect of this disclosure, the state of a battery module can be diagnosed based on the voltage behavior of a plurality of battery cells included in the battery module.

[0028] The effects of this disclosure are not limited to those described above; other unmentioned effects can be clearly understood by those skilled in the art through the description of the claims. Attached Figure Description

[0029] The accompanying drawings illustrate a preferred embodiment of this disclosure and are used together with the foregoing disclosure to provide a further understanding of the technical features of this disclosure; therefore, this disclosure is not to be construed as limited to the drawings.

[0030] Figure 1 This is a schematic diagram illustrating a battery diagnostic device according to an embodiment of the present disclosure.

[0031] Figure 2This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of this disclosure.

[0032] Figure 3 This is a diagram schematically illustrating a battery diagnostic method according to yet another embodiment of the present disclosure.

[0033] Figure 4 This is a diagram schematically illustrating an embodiment of the battery module diagnostic steps in a battery diagnostic method according to yet another embodiment of the present disclosure.

[0034] Figure 5 This is a diagram schematically illustrating another embodiment of the battery module diagnostic steps in a battery diagnostic method according to yet another embodiment of the present disclosure. Detailed Implementation

[0035] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather as meanings and concepts corresponding to various technical aspects of this disclosure, based on the principle of allowing the inventors to appropriately define the terms to obtain the best interpretation.

[0036] Therefore, the description presented herein is merely a preferred example, intended for illustrative purposes only, and is not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications can be made without departing from the scope of this disclosure.

[0037] Furthermore, in describing this disclosure, detailed descriptions of relevant known elements or functions are omitted here where it is believed that such detailed descriptions would obscure the key subject matter of this disclosure.

[0038] Ordinal terms such as “first” and “second” can be used to distinguish an element among various elements, but are not intended to limit the elements by these terms.

[0039] Throughout this specification, when a section is referred to as “comprising” or “including” any element, unless otherwise expressly stated, it means that the section may further include other elements, without excluding other elements.

[0040] Furthermore, throughout the specification, when one part is referred to as "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" and another element is inserted between them.

[0041] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] Figure 1 This is a schematic diagram illustrating a battery diagnostic device 100 according to one embodiment of the present disclosure. Figure 2This is a diagram schematically illustrating an example configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0043] refer to Figure 1 The battery diagnostic device 100 may include a voltage measurement unit 110 and a control unit 120.

[0044] The voltage measurement unit 110 can be configured to measure the voltage of each of the multiple battery cells B included in the battery module BM in each voltage measurement cycle.

[0045] Here, a battery module (BM) may include one or more battery cells connected in series and / or parallel. Furthermore, a battery cell refers to a physically separable, individual cell with a negative terminal and a positive terminal. For example, a pouch-type lithium polymer cell can be considered a battery cell.

[0046] Furthermore, the voltage measurement period can be a preset period, allowing the voltage measurement unit 110 to measure the voltage of each of the multiple battery cells B. For example, the voltage measurement period can be 1 second.

[0047] For example, in Figure 2 In one embodiment, the battery module BM may include five battery cells B1 to B5.

[0048] In addition, Figure 2 In this embodiment, the voltage measurement unit 110 can be connected to a first sensing line SL1, a second sensing line SL2, a third sensing line SL3, a fourth sensing line SL4, a fifth sensing line SL5, and a sixth sensing line SL6. The voltage measurement unit 110 can measure the voltage of the first battery cell B1 via the first sensing line SL1 and the second sensing line SL2, and measure the voltage of the second battery cell B2 via the second sensing line SL2 and the third sensing line SL3. Furthermore, the voltage measurement unit 110 can measure the voltage of the third battery cell B3 via the third sensing line SL3 and the fourth sensing line SL4, measure the voltage of the fourth battery cell B4 via the fourth sensing line SL4 and the fifth sensing line SL5, and measure the voltage of the fifth battery cell B5 via the fifth sensing line SL5 and the sixth sensing line SL6.

[0049] The control unit 120 can be configured to obtain the voltage values ​​of multiple battery cells B from the voltage measurement unit 110 in each voltage measurement cycle.

[0050] For example, in Figure 2In this embodiment, the voltage measurement unit 110 and the control unit 120 can be connected to communicate with each other. The voltage measurement unit 110 can measure the voltage of multiple battery cells B in each voltage measurement cycle and send the measured voltage values ​​to the control unit 120. Therefore, the control unit 120 can obtain the voltage values ​​of multiple battery cells B in each voltage measurement cycle.

[0051] The control unit 120 can be configured to calculate the voltage variation between multiple voltage values ​​of the multiple battery cells B obtained.

[0052] For example, in Figure 2 In this embodiment, the control unit 120 can calculate the voltage change between the voltage values ​​of the first battery cell B1 to the fifth battery cell B5.

[0053] Specifically, the control unit 120 can be configured to calculate the voltage change by calculating the dispersion or standard deviation between multiple voltage values ​​in each voltage measurement cycle. That is, the voltage change calculated by the control unit 120 can be the dispersion or standard deviation of multiple voltage values ​​measured at the same time point.

[0054] The control unit 120 can be configured to calculate the rate of change of voltage among multiple calculated voltage changes in each diagnostic cycle, which is different from the voltage measurement cycle.

[0055] Here, the diagnostic cycle is the period for calculating the voltage change rate, and can be the period used to diagnose the battery module BM. Preferably, the diagnostic cycle can be set to be longer than the voltage measurement cycle. For example, the diagnostic cycle can be set to 100 seconds.

[0056] For example, similar to the aforementioned implementation, assume the voltage measurement cycle is 1 second and the diagnostic cycle is 100 seconds. Since the control unit 120 calculates the voltage changes of multiple battery cells B in each voltage measurement cycle, 100 voltage changes can be calculated by the control unit 120 each time a diagnostic cycle arrives. The control unit 120 can calculate the voltage change rate for the current diagnostic cycle by calculating the average change rate of the 100 voltage changes.

[0057] Specifically, a total of 100 voltage changes can be calculated from the (n-1)th diagnostic cycle to the nth diagnostic cycle. For example, the first to the 100th voltage changes can be calculated based on the voltage measurement cycle (1 second). The control unit 120 can calculate the voltage change rate of the Nth diagnostic cycle by calculating the average change rate of the first and 100th voltage changes using Formula 1 below.

[0058] [Formula 1]

[0059] VRn=(Sm-S1)÷m

[0060] Here, VRn is the voltage change rate in the nth diagnostic cycle. m is the number of voltage changes calculated from the (n-1)th diagnostic cycle to the nth diagnostic cycle. For example, m can be calculated as "diagnostic cycle ÷ voltage measurement cycle". Sm is the voltage change calculated at the end of the nth diagnostic cycle, and S1 is the voltage change calculated at the beginning of the nth diagnostic cycle.

[0061] For example, assuming the diagnostic cycle is 100 seconds, the voltage measurement cycle is 1 second, and the current diagnostic cycle is the third diagnostic cycle. In the third diagnostic cycle, a total of 100 voltage changes can be calculated. That is, in Formula 1, m can be 100 (the result of "100 ÷ 1"). Sm can be the 100th calculated voltage change, and Si can be the first calculated voltage change. According to Formula 1, the voltage change rate (VR3) of the third diagnostic cycle can be calculated using the formula "(S100 - S1) ÷ 100".

[0062] The control unit 120 can be configured to diagnose the battery module BM based on one or more voltage change rates calculated up to the current diagnostic cycle and a preset standard change rate.

[0063] Here, the standard rate of change can be a voltage change rate used as a standard for diagnosing a battery module BM as being in a defective or normal state. Preferably, the standard rate of change can be set to correspond to a battery module BM in the BOL (Start of Life) state. Here, a battery module BM in the BOL state refers to a battery module BM comprising one or more battery cells in the BOL state.

[0064] For example, the control unit 120 can be configured to compare the voltage change rate calculated in the current diagnostic cycle with the standard change rate, and diagnose the battery module BM based on the comparison result.

[0065] The battery diagnostic apparatus 100 according to embodiments of the present disclosure can periodically calculate the voltage change rate of the voltage changes of a plurality of battery cells B. That is, the average change rate of the voltage distribution of the plurality of battery cells B included in the battery module BM can be calculated in each diagnostic cycle. Furthermore, the battery module BM can be diagnosed based on the average change rate of the voltage distribution (average voltage change rate) and the standard change rate. Therefore, the battery diagnostic apparatus 100 can more accurately diagnose the state of the battery module BM by taking into account the voltage behavior of the plurality of battery cells B during the diagnostic cycle.

[0066] Additionally, the control unit 120 provided to the battery diagnostic device 100 may optionally include processors, application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices known in the art to execute the various control logics performed in this disclosure. Furthermore, 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 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 in various well-known ways.

[0067] Furthermore, the battery diagnostic device 100 may also include a storage unit 130. The storage unit 130 may store data or programs necessary for the operation and function of each component of the battery diagnostic device 100, data generated during the execution of operations or functions, etc. There are no particular limitations on the type of storage unit 130, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit 130 may store program code defining the processes executable by the control unit 120.

[0068] For example, the voltages of multiple battery cells B measured by the voltage measurement unit 110 in each voltage measurement cycle and the voltage changes calculated by the control unit 120 can be stored in the storage unit 130. Furthermore, the standard rate of change of the battery module BM in the BOL state can also be pre-stored in the storage unit 130. The control unit 120 can access the storage unit 130 to obtain the multiple voltage changes calculated during the diagnostic cycle and to obtain the preset standard rate of change.

[0069] The following describes an implementation of the control unit 120 diagnosing the battery module BM.

[0070] First, assume the voltage measurement period is 1 second, the diagnostic period is 100 seconds, and the current diagnostic period is the fifth diagnostic period. A first voltage change rate can be calculated for the first diagnostic period (1 to 100 seconds), and a second voltage change rate can be calculated for the second diagnostic period (101 to 200 seconds). Additionally, a third voltage change rate can be calculated for the third diagnostic period (201 to 300 seconds), a fourth voltage change rate for the fourth diagnostic period (301 to 400 seconds), and a fifth voltage change rate for the fifth diagnostic period (401 to 500 seconds).

[0071] The control unit 120 can be configured to compare the voltage change rate calculated in the current diagnostic cycle with the standard change rate, and diagnose the battery module BM based on the comparison result.

[0072] Specifically, when the voltage change rate is less than the standard change rate, the control unit 120 can be configured to diagnose the battery module BM as a normal module.

[0073] For example, when the fifth voltage change rate calculated in the current diagnostic cycle is less than the standard change rate, the control unit 120 can diagnose the battery module BM as a normal module.

[0074] In other words, when the voltage change rate of multiple battery cells B calculated in the current diagnostic cycle is less than the standard change rate, the control unit 120 can diagnose the battery module BM as being in a normal state without comparing the voltage change rate of the current diagnostic cycle with the voltage change rate of the previous diagnostic cycle.

[0075] Conversely, if the voltage change rate is greater than or equal to the standard change rate, the control unit 120 can be configured to diagnose the battery module BM based on the voltage change rate and a preset reference change rate in a previous diagnostic cycle.

[0076] Here, the control unit 120 can be configured to preset the maximum voltage change rate among one or more voltage change rates calculated in the previous diagnostic cycle as the reference change rate.

[0077] For example, suppose that the third voltage change rate is the largest among the first to fourth voltage change rates. The control unit 120 can preset the third voltage change rate, which is the largest among the first to fourth voltage change rates, as a reference change rate before the fifth diagnostic cycle.

[0078] When the voltage change rate is greater than or equal to the standard change rate and less than the reference change rate, the control unit 120 can be configured to diagnose the battery module BM as a normal module.

[0079] For example, when the fifth voltage change rate is equal to or greater than the standard change rate but less than the reference change rate (third voltage change rate), the control unit 120 can diagnose the battery module BM as a normal module in the fifth diagnostic cycle. That is, in the fifth diagnostic cycle, when the fifth voltage change rate of multiple battery cells B is equal to or greater than the standard change rate but less than the reference change rate (third voltage change rate), the control unit 120 can determine that the rate of change of voltage deviation relative to the multiple battery cells B has not increased compared to the previous diagnostic cycle. Therefore, when the voltage change rate in the current cycle is greater than or equal to the standard change rate but less than the reference change rate, the control unit 120 can diagnose the battery module BM as a normal module.

[0080] Conversely, when the rate of voltage change is equal to or greater than the standard rate of change and the reference rate of change, the control unit 120 can be configured to diagnose the battery module BM as a defective module.

[0081] For example, if the voltage change rate (fifth voltage change rate) of the current diagnostic cycle (fifth diagnostic cycle) is equal to or greater than the standard change rate and the reference change rate (third voltage change rate), then the control unit 120 can determine that the rate of change of voltage deviation relative to the multiple battery cells B is equal to or greater than the standard change rate and is increasing compared to previous diagnostic cycles. That is, the control unit 120 can determine that the degree of degradation among the multiple battery cells B included in the battery module BM is uneven in the current cycle. Therefore, the control unit 120 can diagnose the battery module BM as a defective module.

[0082] In summary, if the voltage change rate is less than the standard change rate, the battery diagnostic device 100 can diagnose the battery module BM as a normal module, regardless of the reference change rate. Furthermore, when the voltage change rate is greater than or equal to the standard change rate and less than the reference change rate, the battery diagnostic device 100 can diagnose the battery module BM as a normal module. Finally, when the voltage change rate is equal to or greater than both the standard and reference change rates, the battery diagnostic device 100 can diagnose the battery module BM as a defective module.

[0083] In other words, the battery diagnostic device 100 can consider all of the voltage change rate, standard change rate, and reference change rate during the diagnosis of the battery module BM's condition in the current diagnostic cycle. By comparing the voltage change rate and the standard change rate, the current condition of the battery module BM can be diagnosed compared to the battery module BM in the BOL state. Furthermore, the uneven degradation of the multiple battery cells B of the battery module BM can be diagnosed by comparing the voltage change rate and the reference change rate. Therefore, the battery diagnostic device 100 has the advantage of diagnosing the condition of the battery module BM in more aspects during the current diagnostic cycle.

[0084] In addition, the control unit 120 can be configured to set the maximum voltage change rate among one or more voltage change rates calculated prior to the current diagnostic cycle as the reference change rate.

[0085] For example, as in the previous embodiment, assume that the control unit 120 calculates a first voltage change rate to a fifth voltage change rate, and the fifth voltage change rate is the most recently calculated. The control unit 120 can set the largest voltage change rate among the first to fourth voltage change rates (excluding the fifth voltage change rate) as a reference change rate. Hereinafter, it is assumed that the first voltage change rate is set as the reference change rate.

[0086] The control unit 120 can be configured to compare the magnitude of a reference rate of change and a voltage rate of change, and diagnose the battery module BM based on the comparison results.

[0087] Specifically, when the voltage change rate is equal to or greater than a reference change rate, the control unit 120 can be configured to diagnose the battery module BM as a defective module. For example, when a fifth voltage change rate, set as the voltage change rate, is equal to or greater than a first voltage change rate, set as the reference change rate, the state of the battery module BM can be diagnosed as a defective module.

[0088] Conversely, when the voltage change rate is less than a reference change rate, the control unit 120 can be configured to diagnose the battery module BM as a normal module. For example, when the fifth voltage change rate, which is set as the voltage change rate, is less than the first voltage change rate, which is set as the reference change rate, the state of the battery module BM can be diagnosed as a normal module.

[0089] In embodiments of this disclosure, when the voltage change rate of the battery module BM increases, the control unit 120 can diagnose the battery module BM as a defective module. Here, the increased voltage change rate can be due to an increase in the voltage variation (deviation or standard deviation) of multiple battery cells B. For example, when the voltage deviation of multiple battery cells B increases due to uneven degradation of the multiple battery cells B, the voltage change rate of the battery module BM may increase. Therefore, the battery diagnostic device can diagnose the battery module BM based on a comparison between the voltage change rate and a reference change rate.

[0090] Additionally, the control unit 120 can be configured to diagnose each of the plurality of battery cells B in parallel with the diagnostic battery module BM during each voltage measurement cycle, based on the voltage value corresponding to each of the plurality of battery cells B.

[0091] Specifically, upper and lower voltage limits for the battery cells can be preset. The control unit 120 can diagnose battery cells whose voltage received from the voltage measurement unit 110 is equal to or greater than the upper voltage limit as being in an overvoltage state. Furthermore, the control unit 120 can diagnose battery cells whose received voltage is equal to or less than the lower voltage limit as being in an undervoltage state. The control unit 120 can diagnose battery cells whose voltage is less than the upper voltage limit but greater than the lower voltage limit as being in a normal state.

[0092] In other words, the control unit 120 can diagnose the state of the battery module BM in each diagnostic cycle, and can also diagnose the state of each of the multiple battery cells B in each voltage measurement cycle.

[0093] Therefore, it is beneficial that the state of each of the multiple battery cells B and the state of the battery module BM can be diagnosed by a battery diagnostic device.

[0094] The following describes an implementation of the control unit 120 adjusting the count value and diagnosing the battery module BM based on the adjusted count value.

[0095] The control unit 120 can be configured to determine the state of the battery module BM based on at least one of the voltage change rate, standard change rate, and reference change rate in each diagnostic cycle, and adjust pre-designed values ​​according to the determined state of the battery module BM.

[0096] Here, the count value can have an initial value set to 0 and a minimum value. Additionally, the count value can be adjusted by increasing or decreasing it by 1 using the control unit 120.

[0097] Specifically, when the control unit 120 diagnoses the battery module BM as a defective module, its use can be stopped and a replacement can be requested. In other words, when the battery module BM is diagnosed as a defective module, unlike when it is diagnosed as a normal module, the corresponding battery module BM may be penalized. Therefore, the control unit 120 can be configured to conservatively diagnose the battery module BM as defective based on stricter standards.

[0098] For example, control unit 120 can be configured to decrease the count value when the voltage change rate is less than a standard change rate. In this case, control unit 120 can diagnose battery module BM as a normal module. If the existing count value is 0, the count value can be kept at 0 because the count value cannot be decreased further (since the minimum value is set to 0).

[0099] Furthermore, the control unit 120 can be configured to decrease the count value when the voltage change rate is greater than or equal to the standard change rate and less than the reference change rate. In this case, the control unit 120 can diagnose the battery module BM as a normal module.

[0100] Furthermore, the control unit 120 can be configured to increment the count value when the voltage change rate is equal to or greater than the standard change rate and the reference change rate. In this case, the control unit 120 can be configured to diagnose the battery module BM based on the adjusted count value and the preset standard value, without immediately diagnosing the battery module BM as a defective module.

[0101] Here, the standard value is a preset value and can be set to a natural number.

[0102] Specifically, the control unit 120 can be configured to diagnose the battery module BM as a defective module when the adjusted count value is equal to or greater than a standard value.

[0103] For example, the count value can be increased when the voltage change rate is equal to or greater than the standard change rate and the reference change rate. Furthermore, if the adjusted count value is equal to or greater than the standard value, the battery module BM can be diagnosed as a defective module. That is, the control unit 120 can be configured to diagnose the battery module BM as a defective module when the voltage change rate equals or greater than the standard change rate and the reference change rate occurs at the reference value or more times. Therefore, since the control unit 120 diagnoses the battery module BM as a defective module using stringent standards, the possibility of incorrectly diagnosing a normal module as a defective module can be significantly reduced.

[0104] However, when the voltage change rate is less than the standard change rate, or when the voltage change rate is equal to or greater than the standard change rate but less than the reference change rate, the control unit 120 can decrease the count value. That is, in this case, the adjusted count value will inevitably be less than the standard value. Therefore, even without comparing the adjusted count value with the standard value, the control unit 120 can diagnose the battery module BM as a normal module to prevent unnecessary waste of system resources by using system resources more efficiently.

[0105] The battery diagnostic apparatus 100 according to embodiments of this disclosure can diagnose a battery module BM as a defective module using strict criteria based on count values ​​and standard values. Therefore, the battery diagnostic apparatus can prevent a normal module from being incorrectly diagnosed as a defective module.

[0106] The battery diagnostic device 100 according to this disclosure can be applied to a BMS (Battery Management System). That is, a BMS according to this disclosure may include the aforementioned battery diagnostic device 100. In this configuration, at least some components of the battery diagnostic device 100 can be implemented by supplementing or adding functions included in a conventional BMS configuration. 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 a BMS.

[0107] Furthermore, the battery diagnostic device 100 according to this disclosure can be provided to the battery pack 1. For example, refer to Figure 2 According to this disclosure, the battery pack 1 may include a battery diagnostic device 100 and a battery module BM. Furthermore, the battery pack 1 may also include electrical equipment (relays, fuses, etc.) and a housing.

[0108] Figure 3 This is a diagram schematically illustrating a battery diagnostic method according to yet another embodiment of the present disclosure.

[0109] Preferably, each step of the battery diagnostic method can be performed by the battery diagnostic device 100. In the following text, content that is repeated from the preceding description will be omitted or briefly described.

[0110] refer to Figure 3 The battery diagnostic method may include a voltage measurement step (S100), a voltage change calculation step (S200), a voltage change rate calculation step (S300), and a battery module diagnostic step (S400).

[0111] The voltage measurement step S100 is a step of measuring the voltage of each of the multiple battery cells B included in the battery module BM in each voltage measurement cycle, and can be performed by the voltage measurement unit 110.

[0112] The voltage change calculation step (S200) is a step that calculates the voltage change between multiple voltage values ​​of multiple battery cells B in each voltage measurement cycle, and can be executed by the control unit 120.

[0113] The control unit 120 can receive multiple voltage values ​​for multiple battery cells B from the voltage measurement unit 110 and calculate the voltage change between the multiple received voltage values.

[0114] For example, the control unit 120 can calculate the voltage change by calculating the deviation or standard deviation between multiple voltage values.

[0115] The voltage change rate calculation step (S300) is a step of calculating the voltage change rate between multiple calculated voltage changes in each diagnostic cycle that is different from the voltage measurement cycle, and can be executed by the control unit 120.

[0116] Assuming the voltage measurement cycle is 1 second and the diagnostic cycle is 100 seconds, the control unit 120 can calculate the voltage change of multiple voltage values ​​of multiple battery cells B measured every second. Furthermore, the control unit 120 can calculate the voltage change rate of multiple voltage changes every 100 seconds. In this case, the control unit 120 can calculate the voltage change rate of 100 voltage changes every 100 seconds.

[0117] For example, the control unit 120 can calculate the voltage change rate of the corresponding diagnostic cycle by calculating the average rate of change between the first calculated voltage change and the last calculated voltage change in the corresponding diagnostic cycle.

[0118] The battery module diagnostic step (S400) is a step to diagnose the battery module BM based on one or more voltage change rates calculated up to the current diagnostic cycle and a preset standard change rate, and can be executed by the control unit 120.

[0119] Figure 4 This is a diagram schematically illustrating an embodiment of the battery module diagnostic step (S400) in a battery diagnostic method according to another embodiment of the present disclosure.

[0120] refer to Figure 4 The battery module diagnostic step (S400) may include steps S410 to S440.

[0121] In step S410, the voltage change rate and the standard change rate can be compared. Specifically, the voltage change rate calculated in the current diagnostic cycle and the standard change rate can be compared. If the voltage change rate is equal to or greater than the standard change rate, step S420 can be executed; if the voltage change rate is less than the standard change rate, step S440 can be executed.

[0122] In step S420, the voltage change rate and a reference change rate can be compared. Specifically, the voltage change rate calculated in the current diagnostic cycle can be compared with a preset reference change rate from previous diagnostic cycles. That is, the voltage change rate calculated in the current diagnostic cycle can be compared with the reference change rate that has the maximum value among one or more voltage change rates calculated in previous diagnostic cycles. If the voltage change rate is equal to or greater than the reference change rate, step S430 can be executed; if the voltage change rate is less than the reference change rate, step S440 can be executed.

[0123] In step S430, the battery module BM can be diagnosed as a defective module. That is, if the voltage change rate is equal to or greater than the standard change rate and the reference change rate, the control unit 120 can diagnose the battery module BM as a defective module.

[0124] In step S440, the battery module BM can be diagnosed as a normal module. That is, if the voltage change rate is less than the standard change rate, or if the voltage change rate is equal to or greater than the standard change rate but less than the reference change rate, the control unit 120 can diagnose the battery module BM as a normal module.

[0125] Figure 5 This is a diagram schematically illustrating another embodiment of the battery module diagnostic step (S400) in a battery diagnostic method according to yet another embodiment of the present disclosure.

[0126] refer to Figure 5 The battery module diagnostic step (S400) may include steps S410 to S470. The following will focus on describing... Figure 5 Implementation methods and Figure 4 The differences in the implementation methods.

[0127] In step S410, if the voltage change rate is greater than or equal to the standard change rate, then step S420 is executed; if the voltage change rate is less than the standard change rate, then step S460 is executed.

[0128] In step S420, if the voltage change rate is equal to or greater than the reference change rate, then step S450 is executed; if the voltage change rate is less than the reference change rate, then step S460 is executed.

[0129] In step S450, the count value can be incremented. For example, the count value can have an initial value set to 0 and a minimum value, and can be incremented by 1. That is, if the voltage change rate is equal to or greater than the standard change rate and the reference change rate, the control unit 120 can increment the count value. After the count value is incremented, step S470 can be executed.

[0130] In step S470, the count value can be compared with a standard value. Specifically, if the count value increased in step S450 is greater than or equal to the standard value, step S430 can be executed. Conversely, if the count value increased in step S450 is less than the standard value, step S440 can be executed.

[0131] In step S460, the count value can be decreased. That is, if the voltage change rate is less than the standard change rate, or if the voltage change rate is equal to or greater than the standard change rate but less than the reference change rate, the control unit 120 can decrease the count value. However, the count value may not decrease below the set minimum value. After step S460, step S440 can be executed so that the battery module BM can be diagnosed as a normal module.

[0132] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program that implements functions corresponding to the configuration of the embodiments of this disclosure, or a recording medium on which the program is recorded. Those skilled in the art can easily implement the program or recording medium based on the above description of the embodiments.

[0133] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various variations and modifications within the scope of this disclosure will become apparent to those skilled in the art from this detailed description.

[0134] Furthermore, those skilled in the art can make many substitutions, modifications and variations to the above-described disclosure without departing from multiple technical aspects of the disclosure, and the disclosure is not limited to the above embodiments and the accompanying drawings. Each embodiment can be selectively combined in part or in whole to allow for various modifications.

[0135] (Reference symbols)

[0136] 1: Battery pack

[0137] 100: Battery diagnostic device

[0138] 110: Voltage Measurement Unit

[0139] 120: Control Unit

[0140] 130: Storage unit

[0141] BM: Battery Module

[0142] C: Multiple battery cells

Claims

1. A battery diagnostic device, the battery diagnostic device comprising: A voltage measurement unit, configured to measure the voltage of each of a plurality of battery cells included in a battery module in each voltage measurement cycle; as well as A control unit is configured to obtain voltage values ​​of the plurality of battery cells from the voltage measurement unit in each voltage measurement cycle, calculate the voltage change between the obtained voltage values ​​of the plurality of battery cells, calculate the rate of change between the calculated voltage changes in each diagnostic cycle different from the voltage measurement cycle, and diagnose the battery module based on one or more rate of change calculated up to the current diagnostic cycle, a preset standard rate of change, and a preset reference rate of change in previous diagnostic cycles. The reference rate of change is preset to the maximum voltage rate of change among one or more voltage rates of change calculated in a previous diagnostic cycle.

2. The battery diagnostic device according to claim 1, in, The control unit is configured to compare the voltage change rate calculated in the current diagnostic cycle with the standard change rate, and diagnose the state of the battery module based on the comparison result.

3. The battery diagnostic device according to claim 2, in, The control unit is configured to diagnose the battery module based on the voltage change rate and a reference change rate preset in a previous diagnostic cycle when the voltage change rate is equal to or greater than the standard change rate. The control unit is configured to diagnose the battery module as a normal module when the voltage change rate is less than the standard change rate.

4. The battery diagnostic device according to claim 3, in, The control unit is configured to diagnose the battery module as defective when the voltage change rate is equal to or greater than the standard change rate and the reference change rate. The control unit is configured to diagnose the battery module as a normal module when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate.

5. The battery diagnostic device according to claim 4, in, The control unit is configured to determine the state of the battery module in each diagnostic cycle based on at least one of the voltage change rate, the standard change rate, and the reference change rate, adjust a pre-designed value according to the determined state of the battery module, and diagnose the battery module based on the adjusted count value and the preset standard value.

6. The battery diagnostic device according to claim 5, in, The control unit is configured to diagnose the battery module as a defective module when the adjusted count value is equal to or greater than the standard value.

7. The battery diagnostic device according to claim 5, in, The control unit is configured to decrease the count value when the voltage change rate is less than the standard change rate. The control unit is configured to decrease the count value when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate. The control unit is configured to increment the count value when the voltage change rate is equal to or greater than the standard change rate and the reference change rate.

8. The battery diagnostic device according to claim 7, in, If the count value is 0, then the count value will no longer decrease.

9. The battery diagnostic device according to claim 1, in, The control unit is configured to calculate the voltage change by calculating the deviation or standard deviation of the plurality of voltage values ​​in each voltage measurement cycle.

10. The battery diagnostic device according to claim 1, in, The diagnostic cycle is set to be longer than the voltage measurement cycle.

11. The battery diagnostic device according to claim 1, in, The control unit is configured to diagnose each of the plurality of battery cells based on the voltage value corresponding to each of the plurality of battery cells in each voltage measurement cycle.

12. The battery diagnostic device according to claim 11, in, The control unit diagnoses battery cells whose voltage value received from the voltage measurement unit is equal to or greater than a preset upper limit voltage value as overvoltage, battery cells whose received voltage value is equal to or less than a preset lower limit voltage value as undervoltage, and battery cells whose voltage value is less than the upper limit voltage value but exceeds the lower limit voltage value as normal.

13. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 12.

14. A battery diagnostic method, the battery diagnostic method comprising: A voltage measurement step, which measures the voltage of each of the multiple battery cells included in the battery module in each voltage measurement cycle; The voltage change calculation step calculates the voltage change between multiple voltage values ​​of the multiple battery cells in each voltage measurement cycle. A voltage change rate calculation step, which calculates the voltage change rate among multiple calculated voltage changes in each diagnostic cycle different from the voltage measurement cycle; and The battery module diagnostic steps diagnose the battery module based on one or more voltage change rates calculated up to the current diagnostic cycle, a preset standard change rate, and a preset reference change rate from previous diagnostic cycles. The reference rate of change is configured to be the maximum voltage rate of change among one or more voltage rates of change calculated in a previous diagnostic cycle.

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