Battery diagnosis device and operation method thereof

Abstract

A battery diagnosis device according to an embodiment disclosed in the present document may comprise: a pulse application unit which applies a current pulse to a battery; and a controller which acquires a first voltage corresponding to the current pulse, calculates a frequency-specific impedance of the battery via Fourier transform on the basis of the current pulse and the first voltage, and diagnoses whether an abnormal battery cell is included in the battery on the basis of first information of the battery, which is related to the frequency-specific impedance of the battery.

Description

Battery diagnostic device and its operating method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0178063, filed December 8, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to a battery diagnostic device and an operating method thereof.

[0005] Recently, research and development on secondary batteries has been actively conducted. Here, secondary batteries are rechargeable and include both conventional Ni / Cd and Ni / MH batteries, as well as recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of having a much higher energy density than conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form, making them suitable for use as power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, attracting attention as a next-generation energy storage medium.

[0006] Batteries are managed through a Battery Management System (BMS). The BMS measures or predicts the battery's condition and uses this information to diagnose battery abnormalities. However, battery behavior can vary widely depending on factors such as temperature, State of Charge (SOC), and State of Health (SOH), making accurate diagnosis of abnormalities a challenging task.

[0007] One purpose of the embodiments disclosed in this document is to provide a battery diagnosis device and an operating method thereof capable of calculating frequency-dependent impedance of cells in a battery and diagnosing the battery based on the calculated impedance.

[0008] One purpose of the embodiments disclosed in this document is to provide a battery diagnostic device and an operating method thereof capable of calculating frequency-dependent impedance of a battery based on a response of a pulse applied to the battery.

[0009] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the descriptions below.

[0010] A battery diagnostic device according to one embodiment disclosed in the present document may include a pulse application unit that applies a current pulse to a battery, a controller that obtains a first voltage corresponding to the current pulse, calculates a frequency-dependent impedance of the battery through Fourier transform based on the current pulse and the first voltage, and diagnoses whether the battery includes an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery.

[0011] In one embodiment, the pulse applying unit can apply at least one of a charging current pulse and a discharging current pulse to the battery.

[0012] In one embodiment, the pulse applying unit can alternately apply at least two signals among a charge current pulse, a resting current pulse, and a discharge current pulse to the battery.

[0013] In one embodiment, the first information may include at least one of the real part of the frequency-dependent impedance, the imaginary part of the frequency-dependent impedance, the magnitude of the frequency-dependent impedance, or the phase of the frequency-dependent impedance.

[0014] In one embodiment, the controller calculates a first difference based on a difference between first information at a first frequency and first information at a plurality of frequencies different from the first frequency, and can diagnose whether the battery includes an abnormal battery cell based on the first difference at the plurality of frequencies.

[0015] In one embodiment, the controller may calculate a first difference of each of the plurality of battery cells included in the battery, calculate an average of the first differences of each of the plurality of battery cells, and diagnose an abnormality of the battery based on the average of the first differences and the first difference of each of the plurality of battery cells.

[0016] In one embodiment, the controller calculates a deviation between the average of the first differences and the first differences of each of the plurality of battery cells, and if the deviation is greater than a preset value, it can diagnose that the battery includes an abnormal battery cell.

[0017] In one embodiment, the controller can calculate the deviation within a set frequency range.

[0018] In one embodiment, the first frequency may be the lowest frequency among the frequencies at which the impedance is calculated.

[0019] In one embodiment, the first frequency may be the highest frequency among the frequencies at which the impedance is calculated.

[0020] An operating method of a battery diagnosis device according to one embodiment disclosed in the present document may include an operation of applying a current pulse to a battery, an operation of obtaining a first voltage corresponding to the current pulse, an operation of calculating a frequency-dependent impedance of the battery through a Fourier transform based on the current pulse and the first voltage, and an operation of diagnosing whether the battery includes an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery.

[0021] In one embodiment, the act of applying a current pulse to the battery may apply at least one of a charge current pulse and a discharge current pulse to the battery.

[0022] In one embodiment, the operation of applying a current pulse to the battery may alternately apply at least two signals of a charge current pulse, a rest current pulse, and a discharge current pulse to the battery.

[0023] In one embodiment, the first information may include at least one of the real part of the frequency-dependent impedance, the imaginary part of the frequency-dependent impedance, the magnitude of the frequency-dependent impedance, or the phase of the frequency-dependent impedance.

[0024] In one embodiment, the operation of diagnosing whether the battery includes an abnormal battery cell based on first information of the battery related to impedance by frequency of the battery may include an operation of calculating a first difference based on a difference between first information at a first frequency and first information at a plurality of frequencies different from the first frequency, and an operation of diagnosing whether the battery includes an abnormal battery cell based on the first difference at the plurality of frequencies.

[0025] In one embodiment, the operation of diagnosing whether the battery includes an abnormal battery cell based on the first information of the battery related to the frequency-dependent impedance of the battery may include the operation of calculating a first difference of each of the plurality of battery cells included in the battery, the operation of calculating an average of the first differences of each of the plurality of battery cells, and the operation of diagnosing an abnormality of the battery based on the average of the first differences and the first difference of each of the plurality of battery cells.

[0026] In one embodiment, the operation of diagnosing an abnormality of the battery based on the average of the first differences and the first differences of each of the plurality of battery cells may include the operation of calculating a deviation between the average of the first differences and the first differences of each of the plurality of battery cells, and the operation of diagnosing that the battery includes an abnormal battery cell if the deviation is greater than or equal to a preset value.

[0027] In one embodiment, the operation of calculating a deviation between the average of the first differences and the first differences of each of the plurality of battery cells can calculate the deviation within a set frequency range.

[0028] In one embodiment, the first frequency may be the highest frequency among the frequencies at which the impedance is calculated.

[0029] In one embodiment, the first frequency may be the highest frequency among the frequencies at which the impedance is calculated.

[0030] A battery diagnostic device and its operating method according to one embodiment disclosed in this document can precisely diagnose a battery.

[0031] A battery diagnosis device and its operating method according to one embodiment disclosed in this document can calculate frequency-dependent impedance through Fourier transform, and diagnose a battery based on the calculated frequency-dependent impedance.

[0032] A battery diagnostic device and its operating method according to one embodiment disclosed in this document can determine whether a defective cell exists in a battery.

[0033] In addition, various effects may be provided, either directly or indirectly, through this document.

[0034] FIG. 1 is a block diagram showing a battery diagnostic device according to one embodiment disclosed in this document.

[0035] FIG. 2 is a drawing showing an example of a battery diagnostic device applying a pulse according to one embodiment disclosed in this document.

[0036] FIG. 3 is a diagram showing an example of a result of calculating impedance by frequency by a battery diagnostic device according to one embodiment disclosed in this document.

[0037] FIG. 4 is a drawing showing an example of a battery diagnostic device according to one embodiment disclosed in this document determining whether there is an abnormal battery cell in a battery.

[0038] FIG. 5 is a drawing showing an operation method of a battery diagnostic device according to one embodiment disclosed in this document.

[0039] FIGS. 6 to 8 are flowcharts specifically showing an operation method of a battery diagnostic device according to one embodiment disclosed in this document.

[0040] FIG. 9 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery diagnostic device according to one embodiment disclosed in this document.

[0041] Hereinafter, embodiments disclosed in this document will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments disclosed in this document, detailed descriptions of related known structures or functions will be omitted if they are deemed to hinder understanding of the embodiments disclosed in this document.

[0042] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components and do not limit the nature, order, or sequence of the components. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0043] FIG. 1 is a drawing showing a battery diagnostic device according to one embodiment disclosed in this document.

[0044] Referring to FIG. 1, a battery diagnostic device (100) according to one embodiment disclosed in this document may include a pulse application unit (110) and a controller (120).

[0045] The battery diagnostic device (100) may be a variety of electronic devices for diagnosing or testing a battery. For example, the battery diagnostic device (100) may be a pulse analyzer. The pulse analyzer may be a device that diagnoses whether a battery is abnormal based on a response to a pulse applied to the battery. The pulse analyzer may be included in the in-vehicle BMS (Battery Management System), but may also be implemented as a separate external device distinct from the in-vehicle BMS. In addition, the pulse analyzer may further include a pulse generator for generating pulses; however, this is merely an example, and the pulse generator may be implemented as a separate external device. In the latter case, the battery diagnostic device (100) may receive a response from the battery to the pulse applied to the battery by the pulse generator, and diagnose whether the battery is abnormal based on the response.

[0046] According to another embodiment, the battery diagnostic device (100) may be included in a device for charge / discharge testing, such as a server, a cloud server, or a charge / discharge cycler, or may be included in various devices for diagnosing or testing batteries.

[0047] The pulse application unit (110) can apply a current pulse to the battery. For example, the pulse application unit (110) can apply a plurality of current pulses to the battery.

[0048] According to an embodiment, the pulse application unit (110) may apply at least one of a charging pulse and a discharging pulse to the battery. As another example, the pulse application unit (110) may alternately apply a charging pulse and a discharging pulse to the battery.

[0049] According to an embodiment, the pulse application unit (110) may alternately apply charge pulses and discharge pulses to the battery without setting a rest period between the charge pulses and discharge pulses. According to another embodiment, the pulse application unit (110) may alternately apply charge pulses and discharge pulses to the battery while setting a rest period between the charge pulses and discharge pulses.

[0050] According to an embodiment, the pulse application unit (110) can continuously apply a charging pulse to the battery. For example, the pulse application unit (110) can continuously apply a charging pulse for a set period of time by applying a charging pulse to the battery, setting a pause period, and then applying a charging pulse again.

[0051] According to an embodiment, the pulse application unit (110) can continuously apply a discharge pulse to the battery. For example, the pulse application unit (110) can continuously apply a discharge pulse for a set period of time by applying a discharge pulse to the battery, setting a pause period, and then applying a discharge pulse again.

[0052] According to an embodiment, the pulse application unit (110) can alternately apply a charging pulse, a pause, and a discharge pulse set to a certain condition to the battery. For example, the pulse application unit (110) can apply a pulse to the battery by applying a charging pulse for 0.1 seconds, then applying a discharge pulse for 0.1 seconds with a pause of 0.1 seconds, and repeating the above process. However, the present invention is not limited thereto, and the pulse application unit (110) can apply a pulse to the battery by determining the application time of the charging pulse, whether to apply the charging pulse, whether to pause, the pause time, the application time of the discharge pulse, and whether to apply the discharge pulse.

[0053] According to an embodiment, the pulse application unit (110) can alternately apply charging pulses and discharging pulses multiple times. For example, the pulse application unit (110) can alternately apply charging pulses and discharging pulses 3 to 10 times. However, the present invention is not limited thereto, and the pulse application unit (110) can alternately apply charging pulses and discharging pulses n times (n is a natural number).

[0054] According to an embodiment, the pulse application unit (110) can apply a charge pulse and a discharge pulse as current.

[0055] Such a pulse application unit (110) may be configured to receive a pulse generated by an external device from the external device and apply it to a battery, and may also be configured to generate a pulse based on the control of the controller (120) and apply it to a battery.

[0056] FIG. 2 is a drawing showing an example of a battery diagnostic device applying a pulse according to one embodiment disclosed in this document.

[0057] Referring to FIG. 2, the pulse application unit (110) of the battery diagnostic device (100) can apply pulses to the battery. FIG. 2 illustrates an example in which the pulse application unit (110) alternately applies charge pulses and discharge pulses, but is not limited thereto.

[0058] According to an embodiment, the pulse application unit (110) can apply various pulses to the battery, such as repetition of a charge pulse and a discharge pulse, repetition of a charge pulse and a pause, repetition of a discharge pulse and a pause, or repetition of a charge pulse and a pause and a discharge pulse.

[0059] Referring back to FIG. 1, the controller (120) can obtain a first voltage corresponding to a current pulse. For example, the controller (120) can obtain a voltage corresponding to either a current pulse, a charging pulse, or a discharging pulse as the first voltage.

[0060] According to an embodiment, when a plurality of current pulses are applied from the pulse application unit (110), the controller (120) can obtain a first voltage corresponding to one or all of the plurality of current pulses. As another example, the controller (120) can obtain a voltage response for each of the plurality of current pulses, and can obtain all or part of the obtained voltage responses as the first voltage. For example, the controller (120) can obtain a voltage corresponding to a discharge pulse among the plurality of current pulses as the first voltage, obtain a voltage corresponding to a charge pulse among the plurality of current pulses as the first voltage, or obtain a voltage corresponding to each of a charge pulse and a discharge pulse included in the plurality of current pulses as the first voltage.

[0061] According to an embodiment, the controller (120) may calculate the average voltage as an average of the first voltages corresponding to at least one current pulse. For example, the controller (120) may extract at least one current pulse from among a plurality of current pulses according to a criterion, and may calculate the average voltage as an average of the first voltages corresponding to at least one extracted current pulse. As another example, the controller (120) may calculate the average voltage as an average of the first voltages corresponding to all or part of the current pulses for each of the plurality of current pulses. According to an embodiment, the controller (120) may calculate the average voltage by calculating an average of the first voltages corresponding to current pulses with less noise from among the plurality of current pulses.

[0062] According to an embodiment, when the charge pulse and the discharge pulse are repeated five times, the controller (120) can obtain five first voltages as voltage responses corresponding to the five discharge pulses, and can calculate an average voltage as an average of all or part of the five first voltages. That is, the controller (120) can obtain a first voltage corresponding to one current pulse or multiple current pulses, and can diagnose the battery based on the average voltage of the obtained first voltages. However, the operation of calculating the average voltage of the first voltages corresponding to multiple current pulses may be omitted and performed as an operation for removing noise.

[0063] The controller (120) can calculate the frequency-dependent impedance of the battery through a Fourier transform based on the current pulse and the first voltage. For example, the Fourier transform may include a fast Fourier transform (FFT) or a discrete Fourier transform (DFT).

[0064] According to an embodiment, the controller (120) can Fourier transform a current pulse, Fourier transform a first voltage, and divide the Fourier transformed first voltage by the Fourier transformed current pulse to calculate a Fourier transformed impedance. In addition, the controller (120) can calculate a frequency-dependent impedance based on the Fourier transformed impedance.

[0065] The controller (120) can diagnose whether the battery includes an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery. For example, the first information can include at least one of the real part of the frequency-dependent impedance, the imaginary part of the frequency-dependent impedance, the magnitude of the frequency-dependent impedance, or the phase of the frequency-dependent impedance. According to an embodiment, the controller (120) can diagnose whether the battery includes an abnormal battery cell based on the real part of the frequency-dependent impedance.

[0066] The controller (120) may calculate the first difference based on the difference between the first information at the first frequency and the first information at a plurality of frequencies different from the first frequency. For example, the first frequency may be the lowest frequency among the frequencies for which the impedance is calculated. For another example, the first frequency may be the highest frequency among the frequencies for which the impedance is calculated. In other words, the first frequency may be a reference frequency among the frequencies for which the impedance is calculated.

[0067] The controller (120) can diagnose whether the battery contains an abnormal battery cell based on a first difference at multiple frequencies. For example, the controller (120) can calculate the difference between the real part of the impedance at the first frequency and the real part of the impedance at multiple frequencies, and can diagnose whether the battery contains an abnormal battery cell based on the calculated difference.

[0068] According to an embodiment, a battery may include a plurality of battery cells. The controller (120) may calculate a first difference of each of the plurality of battery cells included in the battery, and may calculate an average of the first differences of each of the plurality of battery cells. In addition, the controller (120) may diagnose an abnormality of the battery based on the average of the first differences and the first differences of each of the plurality of battery cells. For example, the controller (120) may diagnose whether the battery includes an abnormal battery cell based on the average of the first differences and the first differences of each of the plurality of battery cells.

[0069] According to an embodiment, the controller (120) can calculate a deviation between the average of the first differences and the first differences of each of the plurality of battery cells, and if the deviation is greater than a preset value, it can diagnose that the battery contains an abnormal battery cell.

[0070] According to an embodiment, the controller (120) can calculate a deviation within a set frequency range and use it for diagnosis. For example, the set frequency range can include a range from 0.5 Hz to 50 Hz.

[0071] FIG. 3 is a diagram showing an example of a result of calculating impedance by frequency by a battery diagnostic device according to one embodiment disclosed in this document.

[0072] Referring to FIG. 3, the battery diagnostic device (100) can calculate the frequency-dependent impedance of the battery cells included in the battery and check the Nyquist plot. However, checking the Nyquist plot is not a necessary configuration, and the battery diagnostic device (100) can check the real and imaginary parts of the frequency-dependent impedance of the battery cells.

[0073] The controller (120) of the battery diagnostic device (100) can check the impedance (310) of the battery cell at a first frequency. While FIG. 3 illustrates a case where the lowest frequency among the frequencies at which the impedance is calculated is the first frequency, the present invention is not limited thereto. Furthermore, the controller (120) can check the impedance (320) of the battery cell at multiple frequencies different from the first frequency.

[0074] The controller (120) can calculate a first difference (330) between first information related to the impedance of the battery cell at a first frequency and first information related to the impedance of the battery cell at a plurality of frequencies different from the first frequency. For example, the controller (120) can calculate the first difference for each of the plurality of frequencies. Although FIG. 3 illustrates a case where the first information is the real part of the impedance, the present invention is not limited thereto. In addition, although FIG. 3 illustrates an example of calculating the first difference for two frequencies, the present invention is not limited thereto, and the controller (120) can calculate the first difference for all frequencies at which the impedance is calculated.

[0075] In addition, FIG. 3 illustrates an example of showing the impedance of one battery cell by frequency and calculating the first difference for multiple frequencies of one battery cell, but is not limited thereto, and the controller (120) can calculate the impedance of each of the multiple battery cells by frequency and calculate the first difference for each of the multiple frequencies of the multiple battery cells.

[0076] FIG. 4 is a drawing showing an example of a battery diagnostic device according to one embodiment disclosed in this document determining whether there is an abnormal battery cell in a battery.

[0077] Referring to FIG. 4, the controller (120) of the battery diagnostic device (100) according to one embodiment disclosed in the present document can calculate a first difference (510) for the frequency of each of a plurality of battery cells.

[0078] The controller (120) can calculate an average of the first differences of each of the plurality of battery cells, and can calculate a deviation (520) between the average of the first differences and the first differences of each of the plurality of battery cells. For example, the controller (120) can calculate an average of the first differences for each frequency at which the first differences (510) for the frequencies of each of the plurality of battery cells are calculated, and can calculate a deviation between the average of the first differences and the first differences of each battery cell for each calculated frequency. For another example, the deviation can be calculated through the difference, or can be calculated through the standard deviation through a normal distribution, or can be calculated through various methods such as the Root Mean Square (RMS) or the Least Square Mean (LSM).

[0079] The controller (120) can determine whether there is a faulty battery cell among the plurality of battery cells based on the deviation (520) of the first difference of each of the plurality of battery cells. That is, the controller (120) can determine whether there is a faulty battery cell in the battery based on the deviation (520) of the first difference of each of the plurality of battery cells. According to an embodiment, the controller (120) can diagnose whether there is a faulty battery cell in the battery by calculating the deviation in a set frequency range (530).

[0080] Therefore, the battery diagnosis device (100) according to one embodiment disclosed in this document can precisely diagnose a battery.

[0081] A battery diagnostic device (100) according to one embodiment disclosed in this document can calculate impedance by frequency through Fourier transform, and can diagnose a battery based on the calculated impedance by frequency.

[0082] A battery diagnostic device (100) according to one embodiment disclosed in this document can determine whether a defective cell exists in a battery.

[0083] FIG. 5 is a diagram illustrating an operating method of a battery diagnostic device according to one embodiment disclosed in this document. According to the embodiment, the operations illustrated in FIG. 5 may be performed through the battery diagnostic device (100) of FIG. 1.

[0084] Referring to FIG. 5, in operation 510, the pulse application unit (110) may apply a current pulse to the battery. For example, the pulse application unit (110) may apply a plurality of current pulses to the battery.

[0085] According to an embodiment, the pulse application unit (110) may apply at least one of a charging pulse and a discharging pulse to the battery. As another example, the pulse application unit (110) may alternately apply a charging pulse and a discharging pulse to the battery.

[0086] According to an embodiment, the pulse application unit (110) may alternately apply charge pulses and discharge pulses to the battery without setting a rest period between the charge pulses and discharge pulses. According to another embodiment, the pulse application unit (110) may alternately apply charge pulses and discharge pulses to the battery while setting a rest period between the charge pulses and discharge pulses.

[0087] According to an embodiment, the pulse application unit (110) can continuously apply a charging pulse to the battery. For example, the pulse application unit (110) can continuously apply a charging pulse for a set period of time by applying a charging pulse to the battery, setting a pause period, and then applying a charging pulse again.

[0088] According to an embodiment, the pulse application unit (110) can continuously apply a discharge pulse to the battery. For example, the pulse application unit (110) can continuously apply a discharge pulse for a set period of time by applying a discharge pulse to the battery, setting a pause period, and then applying a discharge pulse again.

[0089] According to an embodiment, the pulse application unit (110) can alternately apply a charging pulse, a pause, and a discharge pulse set to a certain condition to the battery. For example, the pulse application unit (110) can apply a pulse to the battery by applying a charging pulse for 0.1 seconds, then applying a discharge pulse for 0.1 seconds with a pause of 0.1 seconds, and repeating the above process. However, the present invention is not limited thereto, and the pulse application unit (110) can apply a pulse to the battery by determining the application time of the charging pulse, whether to apply the charging pulse, whether to pause, the pause time, the application time of the discharge pulse, and whether to apply the discharge pulse.

[0090] According to an embodiment, the pulse application unit (110) can alternately apply charging pulses and discharging pulses multiple times. For example, the pulse application unit (110) can alternately apply charging pulses and discharging pulses 3 to 10 times. However, the present invention is not limited thereto, and the pulse application unit (110) can alternately apply charging pulses and discharging pulses n times (n is a natural number).

[0091] According to an embodiment, the pulse application unit (110) can apply a charge pulse and a discharge pulse as current.

[0092] In operation 520, the controller (120) can obtain a first voltage corresponding to the current pulse. For example, the controller (120) can obtain a voltage corresponding to either a current pulse, a charging pulse, or a discharging pulse as the first voltage.

[0093] According to an embodiment, when a plurality of current pulses are applied from the pulse application unit (110), the controller (120) can obtain a first voltage corresponding to one or all of the plurality of current pulses. As another example, the controller (120) can obtain a voltage response for each of the plurality of current pulses, and can obtain all or part of the obtained voltage responses as the first voltage. For example, the controller (120) can obtain a voltage corresponding to a discharge pulse among the plurality of current pulses as the first voltage, obtain a voltage corresponding to a charge pulse among the plurality of current pulses as the first voltage, or obtain a voltage corresponding to each of a charge pulse and a discharge pulse included in the plurality of current pulses as the first voltage.

[0094] According to an embodiment, the controller (120) may calculate the average voltage as an average of the first voltages corresponding to at least one current pulse. For example, the controller (120) may extract at least one current pulse from among a plurality of current pulses according to a criterion, and may calculate the average voltage as an average of the first voltages corresponding to at least one extracted current pulse. As another example, the controller (120) may calculate the average voltage as an average of the first voltages corresponding to all or part of the current pulses for each of the plurality of current pulses. According to an embodiment, the controller (120) may calculate the average voltage by calculating an average of the first voltages corresponding to current pulses with less noise from among the plurality of current pulses.

[0095] According to an embodiment, when the charge pulse and the discharge pulse are repeated five times, the controller (120) can obtain five first voltages as voltage responses corresponding to the five discharge pulses, and can calculate an average voltage as an average of all or part of the five first voltages. That is, the controller (120) can obtain a first voltage corresponding to one current pulse or multiple current pulses, and can diagnose the battery based on the average voltage of the obtained first voltages. However, the operation of calculating the average voltage of the first voltages corresponding to multiple current pulses may be omitted and performed as an operation for removing noise.

[0096] In operation 530, the controller (120) can calculate the frequency-dependent impedance of the battery through a Fourier transform based on the current pulse and the first voltage. For example, the Fourier transform may include a fast Fourier transform (FFT) or a discrete Fourier transform (DFT).

[0097] According to an embodiment, the controller (120) can Fourier transform a current pulse, Fourier transform a first voltage, and divide the Fourier transformed first voltage by the Fourier transformed current pulse to calculate a Fourier transformed impedance. In addition, the controller (120) can calculate a frequency-dependent impedance based on the Fourier transformed impedance.

[0098] In operation 540, the controller (120) can diagnose whether the battery includes an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery. For example, the first information can include at least one of the real part of the frequency-dependent impedance, the imaginary part of the frequency-dependent impedance, the magnitude of the frequency-dependent impedance, or the phase of the frequency-dependent impedance. According to an embodiment, the controller (120) can diagnose whether the battery includes an abnormal battery cell based on the real part of the frequency-dependent impedance.

[0099] FIGS. 6 to 8 are flowcharts specifically illustrating an operating method of a battery diagnostic device according to one embodiment disclosed in this document. According to the embodiment, the operations illustrated in FIGS. 6 to 8 may be performed through the battery diagnostic device (100) of FIG. 1.

[0100] Referring to FIG. 6, in operation 610, the controller (120) may calculate a first difference based on a difference between first information at a first frequency and first information at a plurality of frequencies different from the first frequency. For example, the first frequency may be the smallest frequency among the frequencies at which impedance is calculated. For another example, the first frequency may be the largest frequency among the frequencies at which impedance is calculated. In other words, the first frequency may be a reference frequency among the frequencies at which impedance is calculated.

[0101] In operation 620, the controller (120) can diagnose whether the battery contains an abnormal battery cell based on a first difference at multiple frequencies. For example, the controller (120) can calculate the difference between the real part of the impedance at the first frequency and the real part of the impedance at multiple frequencies, and can diagnose whether the battery contains an abnormal battery cell based on the calculated difference.

[0102] According to an embodiment, operations 610 and 620 may be performed as included in operation 540 of FIG. 5.

[0103] Referring to FIG. 7, in operation 710, the controller (120) can calculate a first difference of each of the plurality of battery cells included in the battery.

[0104] At operation 720, the controller (120) can calculate an average of the first differences of each of the plurality of battery cells.

[0105] In operation 730, the controller (120) can diagnose an abnormality in the battery based on the average of the first differences and the first differences of each of the plurality of battery cells.

[0106] Actions 710 to 730 may be performed as included in action 540 of FIG. 5. For example, the battery may include a plurality of battery cells.

[0107] Referring to FIG. 8, in operation 810, the controller (120) can calculate the average of the first differences and the deviation of the first differences of each of the plurality of battery cells.

[0108] In operation 820, the controller (120) can diagnose that the battery contains an abnormal battery cell if the deviation is greater than the preset value.

[0109] According to an embodiment, the controller (120) can calculate a deviation within a set frequency range and use it for diagnosis. For example, the set frequency range can include a range from 0.5 Hz to 50 Hz.

[0110] FIG. 9 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery diagnostic device according to one embodiment disclosed in this document.

[0111] Referring to FIG. 9, a computing system (1000) according to one embodiment disclosed in the present document may include an MCU (1010), a memory (1020), an input / output I / F (1030), and a communication I / F (1040).

[0112] The MCU (1010) may be a processor that executes various programs (e.g., pulse generation program, voltage extraction program, impedance calculation program, battery diagnosis program, etc.) stored in the memory (1020), processes various information including battery voltage, battery impedance, presence or absence of abnormal battery cells, etc. through these programs, and performs the functions of the controller included in the battery diagnosis device shown in the aforementioned FIG. 1.

[0113] The memory (1020) can store various programs, such as a pulse generation program, a voltage extraction program, an impedance calculation program, and a battery diagnosis program. In addition, the memory (1020) can store various information, including the voltage of the battery, the impedance of the battery, and the presence or absence of abnormal battery cells.

[0114] Such memories (1020) may be provided in multiple numbers as needed. The memories (1020) may be volatile memories or non-volatile memories. As volatile memories (1020), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (1020), ROM, PROM, EAROM, EPROM, EEPROM, flash memories, etc. may be used. The examples of the memories (1020) listed above are merely examples and are not limited to these examples.

[0115] The input / output I / F (1030) can provide an interface that enables data transmission and reception between an input device (not shown) such as a keyboard, mouse, or touch panel, and an output device (not shown) such as a display and the MCU (1010).

[0116] The communication I / F (1040) is a component capable of transmitting and receiving various data with the server, and may be any device capable of supporting wired or wireless communication. For example, a battery diagnostic device can transmit and receive various information, including battery voltage, battery impedance, and the presence or absence of abnormal battery cells, from a separately provided external server via the communication I / F (1040).

[0117] In this way, a computer program according to one embodiment disclosed in this document may be implemented as a module that is recorded in a memory (1020) and processed by an MCU (1010) to perform each function illustrated in FIG. 1, for example.

[0118] The above description is merely an example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document.

[0119] Accordingly, the embodiments disclosed in this document are intended to illustrate, rather than limit, the technical concepts disclosed in this document, and the scope of the technical concepts disclosed in this document is not limited by these embodiments. The scope of protection of the technical concepts disclosed in this document should be interpreted by the claims below, and all technical concepts within the equivalent scope should be interpreted as being included within the scope of the rights of this document.

[0120]

[0121] [Explanation of symbols]

[0122] 100: Battery Diagnostic Device

[0123] 110: Pulse application unit

[0124] 120: Controller

[0125] 1000: Computing Systems

[0126] 1010: MCU

[0127] 1020: Memory

[0128] 1030: Input / Output I / F

[0129] 1040: Communication I / F

Claims

1. A pulse application unit that applies a current pulse to the battery; and Obtaining a first voltage corresponding to the above current pulse, Based on the current pulse and the first voltage, the frequency-dependent impedance of the battery is calculated through Fourier transform, A battery diagnostic device comprising a controller that diagnoses whether the battery contains an abnormal battery cell based on first information of the battery related to frequency-dependent impedance of the battery.

2. In paragraph 1, The above pulse application part is, A battery diagnostic device that applies at least one of a charge current pulse and a discharge current pulse to the battery.

3. In paragraph 1, The above pulse application part is, A battery diagnostic device that alternately applies at least two signals among a charge current pulse, a rest current pulse, and a discharge current pulse to the battery.

4. In paragraph 1, The above first information is, A battery diagnostic device comprising at least one of the real part of the frequency-specific impedance, the imaginary part of the frequency-specific impedance, the magnitude of the frequency-specific impedance, or the phase of the frequency-specific impedance.

5. In paragraph 1, The above controller, A first difference is calculated based on the difference between the first information at the first frequency and the first information at multiple frequencies different from the first frequency, A battery diagnostic device that diagnoses whether the battery contains an abnormal battery cell based on a first difference in the plurality of frequencies.

6. In paragraph 5, The above controller, Calculating the first difference of each of the plurality of battery cells included in the above battery, Calculating the average of the first differences of each of the plurality of battery cells, A battery diagnostic device that diagnoses an abnormality in the battery based on the average of the first differences and the first differences of each of the plurality of battery cells.

7. In paragraph 6, The above controller, Calculating the average of the first difference and the deviation of the first difference of each of the plurality of battery cells, A battery diagnostic device that diagnoses that the battery contains an abnormal battery cell when the above deviation is greater than a preset value.

8. In paragraph 7, The above controller, A battery diagnostic device which calculates the above deviation within a set frequency range.

9. In paragraph 5, The above first frequency is, A battery diagnostic device, which is the smallest frequency among the frequencies at which impedance is calculated.

10. In paragraph 5, The above first frequency is, A battery diagnostic device, which is the highest frequency among the frequencies at which the impedance is calculated.

11. The act of applying a current pulse to the battery; An operation of obtaining a first voltage corresponding to the above current pulse; An operation of calculating the frequency-dependent impedance of the battery through Fourier transform based on the current pulse and the first voltage; and An operating method of a battery diagnostic device, comprising: an operation of diagnosing whether the battery includes an abnormal battery cell based on first information of the battery related to frequency-dependent impedance of the battery; 12. In paragraph 11, The operation of applying a current pulse to the above battery is: A method of operating a battery diagnostic device, wherein at least one of a charge current pulse and a discharge current pulse is applied to the battery.

13. In paragraph 11, The operation of applying a current pulse to the above battery is: An operating method of a battery diagnostic device, wherein at least two signals among a charge current pulse, a resting current pulse, and a discharge current pulse are alternately applied to the battery.

14. In paragraph 11, The above first information is, An operating method of a battery diagnostic device, comprising at least one of a real part of the frequency-specific impedance, an imaginary part of the frequency-specific impedance, a magnitude of the frequency-specific impedance, or a phase of the frequency-specific impedance.

15. In paragraph 11, An operation of diagnosing whether the battery contains an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery, An operation of calculating a first difference based on a difference between first information at a first frequency and first information at a plurality of frequencies different from the first frequency; and An operating method of a battery diagnostic device, comprising: an operation of diagnosing whether the battery includes an abnormal battery cell based on a first difference in the plurality of frequencies; 16. In paragraph 15, An operation of diagnosing whether the battery contains an abnormal battery cell based on first information of the battery related to the frequency-dependent impedance of the battery, An operation of calculating a first difference of each of a plurality of battery cells included in the battery; An operation of calculating an average of the first differences of each of the plurality of battery cells; and An operation method of a battery diagnosis device, comprising: an operation of diagnosing an abnormality of the battery based on an average of the first differences and the first differences of each of the plurality of battery cells; 17. In paragraph 16, An operation of diagnosing an abnormality of the battery based on the average of the first difference and the first difference of each of the plurality of battery cells is performed. An operation of calculating a deviation between the average of the first difference and the first difference of each of the plurality of battery cells; and A battery diagnostic device, comprising: an operation for diagnosing that the battery contains an abnormal battery cell when the above deviation is greater than or equal to a preset value; 18. In paragraph 17, The operation of calculating the average of the first difference and the deviation of the first difference of each of the plurality of battery cells is: A method of operating a battery diagnostic device, wherein the deviation is calculated within a set frequency range.

19. In paragraph 15, The above first frequency is, A method of operating a battery diagnostic device, wherein the frequency is the highest among the frequencies at which the impedance is calculated.

20. In paragraph 15, The above first frequency is, A method of operating a battery diagnostic device, wherein the frequency is the highest among the frequencies at which the impedance is calculated.

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