BATTERY MANAGEMENT DEVICE, BATTERY MANAGEMENT METHOD AND PROGRAM

Abstract

A battery management device, a battery management procedure, and a program are provided that are capable of detecting an anomaly in a circuit that monitors the battery voltage of a lithium-ion secondary battery. A battery management device (10) comprises a first measuring circuit (15) configured to measure the battery voltage of a lithium-ion secondary battery, a second measuring circuit (16) configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and to measure the amplitude of a resonant electrical signal, and an anomaly detection unit (23) configured to calculate the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and to detect an anomaly in the first measuring circuit (15) based on the calculated battery voltage.

Description

BACKGROUND

[0001] The present disclosure relates to a battery management device, a battery management method and a program.

[0002] It is desirable to suppress the increase of lithium (Li) deposits in a lithium-ion secondary battery in order to prevent a deterioration in the battery's performance. Patent literature 1 discloses a technology for detecting lithium deposits within a lithium-ion secondary battery by applying a high-frequency signal to the battery.

[0003] Patent literature 1: Japanese unexamined patent application no. 2022-108602 OVERVIEW

[0004] It might be possible to use a technology for applying a high-frequency signal to a lithium-ion secondary battery and for measuring the amplitude of a resonant electrical signal to detect an anomaly in a circuit that monitors a battery voltage.

[0005] The present disclosure was made to solve such a problem and provides a battery management device, a battery management method and a program that are capable of detecting an anomaly in a circuit that monitors the battery voltage of a lithium-ion secondary battery.

[0006] A battery management device according to the present disclosure comprises a first measuring circuit configured to measure the battery voltage of a lithium-ion secondary battery, a second measuring circuit configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and to measure the amplitude of a resonant electrical signal, and an anomaly detection unit configured to calculate the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and to detect an anomaly in the first measuring circuit based on the calculated battery voltage.

[0007] A battery management method according to the present disclosure comprises: measuring a battery voltage of a lithium-ion secondary battery using a first measuring circuit, applying a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and measuring an amplitude of a resonant electrical signal, and calculating the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and detecting an anomaly in the first measuring circuit based on the calculated battery voltage.

[0008] A program according to the present disclosure is a program for a battery management device, wherein the battery management device comprises: a first measuring circuit configured to measure the battery voltage of a lithium-ion secondary battery; and a second measuring circuit configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and to measure the amplitude of a resonant electrical signal, wherein the program is configured to cause the battery management device to perform a process for calculating the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and for detecting an anomaly in the first measuring circuit based on the calculated battery voltage.

[0009] According to the present disclosure, it is possible to provide a battery management device, a battery management method and a program that are capable of detecting an anomaly in a circuit that monitors the battery voltage of a lithium-ion secondary battery.

[0010] The above-mentioned and other objectives, features and advantages of the present disclosure are explained in more detail with reference to the detailed description below and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an example of a battery management device according to a first embodiment; Fig. 2 is a circuit diagram showing an example of a second measuring circuit according to the first embodiment; Fig. 3 is a diagram to illustrate an operation performed by the second measuring circuit according to the first embodiment; Fig. Figure 4 is a diagram illustrating an example of changes to a damped vibration waveform according to the first embodiment; and Fig. Figure 5 is a flowchart showing an example of operations performed by the battery management device according to the first embodiment. DESCRIPTION OF THE EXECUTION FORMS

[0011] Embodiments according to the present disclosure are described below with reference to the drawings. However, the present disclosure is not limited to the embodiments described below. Furthermore, the following description and the drawings have been suitably simplified to clarify the explanation. First embodiment

[0012] Fig. Figure 1 is a block diagram showing an example of a battery management device 10 according to a first embodiment. The battery management device 10 manages the use of a manufactured lithium-ion secondary battery (cell 30). The cell 30 can be used, for example, for a vehicle drive system or a household power supply system.

[0013] First, cell 30, for which the measurement is performed, is described. Cell 30 is a lithium-ion secondary battery. Cell 30 can, for example, comprise a positive electrode, a negative electrode, and an ion-conducting medium located between the positive and negative electrodes, which conducts charge carrier ions. The positive electrode can contain a sulfide containing a transition metal element, an oxide containing lithium and a transition metal element, or the like as the positive electrode active material. For example, a lithium-manganese compound oxide, whose basic compositional formula is Li( 1-x )MnO2 (0 <x<1 oder dergleichen, das Gleiche gilt im Folgenden), Li( 1-x )Mn2O4, or the like, a lithium-cobalt compound oxide, whose basic compositional formula is Li( 1-x)CoO2 or the like, a lithium-nickel composite oxide, whose basic compositional formula is Li( 1-x )NiO2 or the like, or a lithium-nickel-cobalt-manganese composite oxide, whose basic compositional formula is Li( 1-x )Ni a Co b Mn cO2 (a+b+c=1) or the like can be used. It should be noted that the term "basic composition formula" means that other elements may be included. The negative electrode can contain a carbon material, a lithium-containing composite oxide, or the like as the negative electrode active material. Examples of electrode active materials include inorganic compounds such as lithium, lithium alloys, and tin compounds; carbon materials capable of absorbing and releasing lithium ions; composite oxides containing multiple elements; and conductive polymers. Examples of carbon materials include coke, glassy carbon, graphite, non-graphitizable carbon, pyrolytic carbon, and carbon fibers. Among these, graphite, such as synthetic and natural graphite, is preferred. Examples of composite oxides include lithium-titanium composite oxides and lithium-vanadium composite oxides.The ion-conducting medium can be, for example, an electrolyte in which a carrier salt is dissolved. Examples of carrier salts include lithium salts, such as LiPF6 and LiBF4. Examples of solvents for electrolytes include carbonates, esters, ethers, nitriles, furans, sulfolanes, and dioxolanes. Only one of these can be used, or two or more can be mixed. Examples of carbonates include, for example: cyclic carbonates such as ethylene carbonate, propylene carbonate, vinylene carbonate, butylene carbonate, and chloroethylene carbonate; and chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl n-butyl carbonate, methyl tert-butyl carbonate, dipropyl carbonate, and tert-butyl propyl carbonate.Furthermore, the ion-conducting medium can be a solid ion-conducting polymer, a mixture of an inorganic solid electrolyte or an organic polymer electrolyte and an inorganic solid electrolyte, an inorganic solid powder bound by an organic binder, or the like. A separator can be arranged between the positive and negative electrodes of the solid electrolyte or cell 30.

[0014] The battery management device 10 comprises as its main hardware configuration a control unit 11, a storage unit 12, a communication unit 13, an interface unit 14 (IF), a first measurement circuit 15 and a second measurement circuit 16. The control unit 11, the storage unit 12, the communication unit 13, the interface unit 14, the first measurement circuit 15 and the second measurement circuit 16 are interconnected via a data bus or the like.

[0015] The control unit 11 is, for example, a processor such as a CPU (Central Processing Unit). The control unit 11 functions as an arithmetic logic unit (ALU), executing control and computational processes. It should be noted that the control unit 11 can comprise multiple processors. The control unit 11 can include a processor mounted on a substrate on which the second measuring circuit 16 is mounted.

[0016] Memory unit 12 is, for example, a storage device such as a memory module or a hard disk drive. Memory unit 12 is, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). Memory unit 12 has a function for storing, for example, a control program and an arithmetic program that are executed by control unit 11. The memory stores one or more instructions. Furthermore, memory unit 12 also has a function for temporarily storing processing data. Memory unit 12 can include a database. In addition, memory unit 12 can include multiple memory modules.

[0017] The communication unit 13 is an interface for communication with other devices via a network. The interface unit 14 is, for example, a user interface (UI). The interface unit 14 includes an output device such as a display or a speaker. The interface unit 14 can also include an input device such as a keyboard, a touch panel, or a mouse. The interface unit 14 can be configured so that an input device and an output device are integrated, for example, in the form of a touchscreen (touch panel).

[0018] The first measuring circuit 15 measures the battery voltage of cell 30. The first measuring circuit 15 can be any circuit or similar device capable of measuring the voltage of cell 30. The specific configuration of the first measuring circuit 15 is known.

[0019] The second measuring circuit 16 comprises a resonant circuit for applying a high-frequency signal of 0.1 MHz or higher to cell 30. The frequency of the high-frequency signal can be 0.5 MHz or higher. The resonant circuit can, for example, be an LCR resonant circuit. Applying a high-frequency signal to cell 30 produces a damped oscillatory waveform in which the amplitude of the resonating electrical signal gradually decays. The second measuring circuit 16 measures the amplitude of the resonating electrical signal. The damping rate (or decay rate) of the damped oscillatory waveform is obtained from amplitude values ​​measured at two different time points, and the deposition of Li in cell 30 is detected based on the damping rate. The measured amplitude is further used to detect an anomaly in the first measuring circuit 15.

[0020] Fig. Figure 2 is a circuit diagram showing an example of the second measurement circuit 16. The second measurement circuit 16 comprises a resonant circuit 41, a sensor buffer circuit 42, and an amplitude measurement circuit 43. It should be noted that the circuit configuration of the second measurement circuit 16 does not correspond to the one shown in Figure 2. Fig. The range shown in Figure 2 is limited. For example, a peak-hold circuit 432 of the second measuring circuit 16 can be a peak-hold circuit comprising a diode. Alternatively, the second measuring circuit 16 can be a circuit that detects the waveform of a damped oscillatory current flowing through the resonant circuit 41 by using a high-speed analog-to-digital converter.

[0021] Cell 30, for which the measurement is performed, is represented by an equivalent circuit diagram in which an inductance L bat , a resistor R bat and a capacity C batare connected in series. The capacitors at both ends of the capacitor C bat The applied voltage corresponds to the battery voltage V bat The inductance L bat represents the parasitic inductance in cell 30. The resistance R bat corresponds to the real part of the impedance of cell 30. The capacitance C bat represents the parasitic capacity in cell 30.

[0022] The resonant circuit 41 includes an inductance L res , a capacity C res , a resistor R res and a SW switch res The inductance L res is also referred to as resonant inductance. The inductance L res can be formed by a winding. The inductance L res is with the inductance L sec coupled to the amplitude measurement circuit 43 and forms, together with the inductance L sec a transformer. The inductance L secIt can also be formed by a winding. The capacitance C res is also called resonant capacitance. The capacitance C res It can be a capacitor, which is a passive element. Alternatively, the capacitance can be C. res It could be a capacitive active element, for example a varicap. The SW switch res It can be a semiconductor switch or a mechanical switch.

[0023] One end of the inductance L res is connected to the positive electrode of cell 30, and the other end is connected to one end of capacitor C res connected. The other end of capacity C res is connected to one end of the SW switch res connected, and the other end of the SW switch res is connected to the negative electrode of cell 30. A discharge resistor R res is parallel to capacity C res switched on.

[0024] The sensor buffer circuit 42 sends a control signal to the switch SW. res The control signal can be generated by the control unit 11. The sensor buffer circuit 42 can activate the switch SW. res The control signal is controlled via a buffer B and a capacitor C1. The control signal rises from a low level to a high level, remains at the high level for a predetermined time, and then falls from the high level back to the low level. When the control signal is at the high level, the switch SW is opened. res switched on. The SW switch res The switch is pulsed into a continuous state according to the control signal. It should be noted that "pulsed into a continuous state" refers to a series of processes in which the SW switch... reschanges from an off state to an on state, is held in the on state for a predetermined time, and then changes from the on state to the off state.

[0025] If the SW switch res As the cell transitions from a pulsed to a continuous state, a pulse voltage, determined based on the output voltage of cell 30, is applied from the positive electrode of cell 30 to the resonant circuit 41. Consequently, a damped oscillatory current, which gradually decays while oscillating at the resonant frequency, flows through the resonant circuit 41. The decay of the damped oscillatory current is due to losses caused by the discharged resistance R. res and the resistance R bat are caused. An induced electromotive force with a damped oscillation waveform is generated in the inductance L. seccorresponding to the damped oscillatory current generated by the inductance L res flows

[0026] The amplitude measurement circuit 43 includes an inductor L sec , a gain circuit 431 and a peak hold circuit 432. As described above, the inductance L sec with the inductance L res coupled to the resonant circuit 41. The amplification circuit 431 amplifies the signal in the inductor L. sec generated induced electromotive force. The amplification circuit 431 can, for example, be a differential amplification circuit formed from an operational amplifier OP1 and resistors R1 to R4.

[0027] The peak hold circuit 432 includes a comparator CMP, a switch SW sp , a switch SW ch , a switch SW dch, a resistor R5, a capacitor C2 and an operational amplifier OP2. The peak-hold circuit 432 holds the peak value of the damped oscillatory waveform, which is amplified by the gain circuit 431, in response to the input of a control signal to control the on / off switching of the switch SW. sp The control signal can be generated by control unit 11.

[0028] The comparator CMP compares the amplified induced electromotive force with a voltage fed back from the operational amplifier OP2 and outputs a high level when the amplified induced electromotive force is greater, and a low level in the other cases. One end of the switch SW sp is connected to the output terminal of the comparator CMP, and the switching on / off of the SW switch ch is determined according to the output signal from the other end of the switch SW spcontrolled. If the output of the comparator CMP is a high level, the SW switch is activated. ch switched on. One end of capacitor C2 is connected via resistor R5 and switch SW. ch connected to a supply potential, and the other end of capacity C2 is connected to a mass potential.

[0029] If or after the SW switch res When the resonance circuit 41 is switched on, the switch SW sp The switch is turned on and then off again after a predetermined time. Capacitor C2 is then charged according to the result of the comparison by comparator CMP. To discharge the charge stored in capacitance C2, switch SW is turned on. dch , which is in the off state, is switched on. The control signal of the SW switch dch can also be generated by control unit 11.

[0030] Operational amplifier OP2 acts as a voltage follower and feeds the voltage applied to capacitor C2 back into the negative input terminal of comparator CMP. Operational amplifier OP2 outputs the peak value of the damped oscillation waveform, which has been amplified by amplification circuit 431. Amplitude measurement circuit 43 may also include an analog-to-digital converter (ADC) to convert the analog signal output by operational amplifier OP2 into a digital signal.

[0031] The operation performed by the second measuring circuit 16 is described with reference to Fig. 3 described. The horizontal axis indicates time, and the vertical axis indicates voltage. A waveform W1 represents the damped oscillation waveform, which is amplified by the amplification circuit 431. A time t0 represents a time at which the switch SW resThe resonance circuit 41 is switched on. The times t1 and t2 represent the times at which the switch SW is switched on. sp The peak hold circuit 432 is switched on. A voltage V ph (t1) represents the output voltage of the operational amplifier OP2 when the switch SW is closed. sp The peak hold circuit 432 is switched on at time t1. A voltage V ph (t2) represents the output voltage of the operational amplifier OP2 when the switch SW is closed. sp The peak hold circuit 432 is switched on at time t2.

[0032] It should be noted that in practice the voltages V ph (t1) and V ph (t2) cannot be held within one cycle of the damped oscillation waveform. That is, in practice, a process for turning on the SW switch resand thus to generate a damped oscillation waveform at time t0 and a process to switch on the SW switch sp and thus, to start the peak value maintenance at time t1 or t2, it is repeated successively, and the output voltage of the operational amplifier OP2 gradually follows the voltage V ph (t1) or V ph (t2) on.

[0033] One in Fig. Waveform W2 shown in Figure 4 represents a damped oscillation waveform generated when a high-frequency signal is applied to cell 30 in its initial state. A vertical arrow indicates a time when switch SW resThe envelope of waveform W2 is represented by a dotted line. If, for example, Li is deposited in cell 30, a damped vibrational waveform is obtained, whose envelope is a curved line represented by a dashed line. Therefore, it is possible to determine whether Li has been deposited or not based on the damping rate of the damped vibrational waveform.

[0034] Referring to Fig. The battery management device 10 comprises the following functions: an impedance measuring unit 21, a lithium detection unit 22, and an anomaly detection unit 23. These functions can be implemented, for example, by executing a program under the control of the control unit 11. More precisely, each function can be implemented by the control unit 11 executing a program (commands) stored in the memory unit 12. Alternatively, each function can be implemented by hardware, such as a circuit or a semiconductor chip.

[0035] The impedance measuring unit 21 measures the real part of the impedance of cell 30 based on the attenuation rate of the amplitude of the electrical signal measured by the second measuring circuit 16. For example, the impedance measuring unit 21 can measure the real part R batCalculate the impedance of cell 30 based on the damping rate α of the amplitude of the electrical signal using equation (10) described below.

[0036] Next, an example of a method for calculating the real part R will be given. bat The impedance of cell 30 is described with reference to mathematical expressions. The voltage V res (t), which connects to the positive terminal of the in Fig. The comparator CMP shown in section 2 is applied and is expressed by expressions (1) to (6). L s In expression (1) is a combined inductance of the inductance L res and the inductance L bat , which are connected in series, and is calculated by expression (3). M in expression (1) represents the mutual inductance between the inductances L res and the inductance L secα in expression (1) is the damping rate of the resonance signal. ω0 in expression (1) is the resonance angular velocity and is calculated by expression (5). Cs in expression (5) is a combined capacitance of capacitance C. res and the capacity C bat , which are connected in series, and is calculated by expression (2). β in expression 1 is a phase difference of the resonance signal and is expressed by expression (6). [Expression 1] Vres(t)=MVbatLsα2ω03+1e−αtcos(ω0t+β) [Expression 2] Cs=Cres+CbatCres+Cbat≒Cres [Expression 3] Ls=Lres+Lbat≒Lres [Expression 4] α=Rbat2Ls+12CresRres [Expression 5] ω0=Rres+RbatRresLsCs−α2 [Expression 6] β=arcsin(e−αtLsα2ω02+1)

[0037] The resonance voltage V res (t n The value at an nth resonance point is expressed by expression (7). nFor example, it represents a point in time at which the Fig. The damped vibration waveform W1 shown in Figure 3 exhibits a peak value. V res (t n ) corresponds, for example, to V ph (t1) or V ph (t2) in Fig. 3. [Expression 7] Vres(tn)=MVbatLsα2ω02+1e−αtn

[0038] For any n=n1 and n=n2 (n1>n2) the damping rate α is calculated by expression (8). [Expression 8] α=1tn2−tn1ln|Vres(tn1)||Vres(tn2)|

[0039] If R res >> R bat ω0 is expressed by expression (9). [Expression 9] ω0=1LsCs−α2

[0040] R bat This represents the real part of the impedance of the lithium-ion secondary battery, as described above. Since the capacity C bat Since the cell 30 is very small, the imaginary part of the impedance is given by L batAs shown. Based on expressions (3) and (4) shown above, expression (10) holds (i.e., is obtained). Furthermore, based on expressions (3) and (9) shown above, expression (11) holds (i.e., is obtained). [Expression 10] Rbat=2(Lres+Lbat){α−12CresRres} [Expression 11] Lbat=1Cs1ω02+α2−Lres

[0041] For example, L bat from expression (11) based on the damping rate α and the resonance frequency ω0, which were calculated using equations (8) and (9) shown above. n2 -t n1 In expression (8) can be approximated by t2-t1, as in Fig. 3 shown. Then R bat from expression (10) based on L bat calculated.

[0042] Referring to Fig. 1 detects the lithium detection unit 22 of the battery management device 10 based on R bat, which was calculated by the impedance measuring unit 21, that Li has been deposited in cell 30. The lithium detection unit 22 can, for example, detect that Li has been deposited if R bat is smaller than a reference value. The reference value can be based on the initial value or similar of R. bat or determined based on manufacturing data or material data of cell 30. If lithium has accumulated in cell 30, the control unit 11 can reduce the charging current or charging power of cell 30.

[0043] The anomaly detection unit 23 calculates the battery voltage V bat the cell 30 from the amplitude of the resonating electrical signal and detects an anomaly in the first measuring circuit 15 based on the calculated battery voltage V batThis means that the anomaly detection unit 23 calculates the battery voltage of cell 30 from the amplitude of the resonating electrical signal by inverse calculation and detects that an anomaly has occurred in the first measuring circuit 15 if the calculated battery voltage deviates from the voltage measured by the first measuring circuit 15. In the event that the second measuring circuit 16 measures the amplitude of the electrical signal at two different times t n1 and t n2 When measuring, the anomaly detection unit 23 can calculate the battery voltage from one of the measured amplitudes.

[0044] As shown in equation (7) above, M and L s as can be seen from the information on the construction of the second measuring circuit 16, and α is calculated from equation (8) and ω0 is calculated from equation (9). If t n is known, V battherefore by inverse calculation from the amplitude V res (t n ) of the resonance signal can be calculated. It should be noted that t n can be calculated using equation (6) shown above. For example, if V res (t n ) in equation (1) shown above has a maximum value, the phase is defined as ω0*t n +β=2π*n (n is an integer), and the ratio between β and t n is determined on the basis of equation (6) such that t n can be calculated. For example, candidates for t can be derived from the ratio described above with respect to the phase. n obtained by numerical calculation or the like, and a candidate immediately after the time at which the leading position is started (e.g. t1 or t2 in Fig. 3), can be considered t n be defined.

[0045] It should be noted that the time t nThe point in time at which the amplitude is maximized can be approximated by the point in time at which peak holding begins (example: t1 or t2). Alternatively, if the second measuring circuit 16 detects a damped oscillation waveform, the anomaly detection unit 23 can determine the time at which the peak holding begins (example: t1 or t2). n determine based on the recorded waveform data.

[0046] If the difference between the battery voltage calculated from the amplitude of the resonating electrical signal and the battery voltage measured by the first measuring circuit 15 exceeds a threshold, the anomaly detection unit 23 can detect that an anomaly has occurred in the first measuring circuit 15.

[0047] If an anomaly is detected in the first measuring circuit 15, the anomaly detection unit 23 can output information via the interface unit 14 indicating that an anomaly has occurred in the first measuring circuit 15. Alternatively, the anomaly detection unit 23 can write (i.e., store / log) data indicating that an anomaly has occurred in the first measuring circuit 15 to the storage unit 12. If an anomaly is detected in the first measuring circuit 15, the battery management device 10 can monitor the battery voltage of cell 30 based on the battery voltage calculated by the anomaly detection unit 23.

[0048] The anomaly detection unit 23 can transmit information indicating that an anomaly has occurred in the first measuring circuit 15 to an external server or communication terminal via the communication unit 13. An operator can then repair or replace the first measuring circuit 15 based on the information received from the server or similar device.

[0049] Fig. Figure 5 is a flowchart showing an example of the operations performed by the battery management device 10. First, the first measuring circuit 15 of the battery management device 10 measures the battery voltage of cell 30 (step S11). Next, the second measuring circuit 16 of the battery management device 10 applies a high-frequency current of 0.1 MHz or higher to cell 30 and measures the amplitude of the resonating electrical signal (step S12). Next, the anomaly detection unit 23 of the battery management device 10 calculates the battery voltage of cell 30 from the amplitude of the resonating electrical signal and detects an anomaly in the first measuring circuit 15 based on the result of the calculation (step S13).If an anomaly is detected in the first measuring circuit 15 (Yes in step S13), the anomaly detection unit 23 outputs information indicating that an anomaly has occurred in the first measuring circuit 15 (step S14). If no anomaly is detected in the first measuring circuit 15 (No in step S13) or after step S14, the battery management device 10 terminates the series of processes.

[0050] The in Fig. The sequence of processes shown in Figure 5 can be carried out at regular intervals. Alternatively, the sequence shown in Figure 5 can be performed at regular intervals. Fig. The sequence of processes shown in Figure 5 is performed if the measurement result from the first measuring circuit 15 is abnormal. If the measurement result from the first measuring circuit 15 is abnormal, there is a possibility that an anomaly has occurred in cell 30 or in the first measuring circuit 15. The battery management device 10 can be activated by performing the steps shown in Figure 5. Fig.The sequence of processes shown in Figure 5 determines whether the anomaly occurred in cell 30 or in the first measuring circuit 15. For example, an operator can repair or replace cell 30 or the first measuring circuit 15, where the anomaly occurred, based on the result of the detection by the anomaly detection unit 23.

[0051] In the first embodiment, it is possible to detect an anomaly in a circuit that measures the voltage of a lithium-ion secondary battery.

[0052] Although embodiments according to the present disclosure have been described above, the present disclosure includes any modifications which do not impair the subject matter and advantages of the present disclosure and is not limited to the embodiments described above.

[0053] The first and second measuring circuits 15 and 16 need not be provided in every single cell, but can instead be provided in only one or more specific cells. Furthermore, the first and second measuring circuits 15 and 16 can be provided in every battery module or battery pack in which several cells are combined.

[0054] The aforementioned program comprises instructions (or software code) which, when loaded into a computer, cause the computer to perform one or more of the functions described in the embodiments. The program may be stored on a non-transitory, computer-readable medium or a tangible storage medium. For example, and without limitation, computer-readable media or tangible storage media may include working memory (RAM), read-only memory (ROM), flash memory, a solid-state drive (SSD) or other types of storage technologies, a CD-ROM, a digital versatile disc (DVD), a Blu-ray disc (registered trademark) or other types of optical storage media, as well as magnetic cartridges, magnetic tapes, magnetic disk storage, or other types of magnetic storage devices. The program may be transferred on a temporary computer-readable medium or a communication medium.For example, and without limitation, temporary computer-readable media or communication media may include electrical, optical, acoustic, or other forms of propagation signals.

[0055] It is evident from the disclosure thus described that the embodiments of the disclosure can be varied in many respects. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure, and all such modifications, which would be obvious to a person skilled in the art, are to be included in the scope of the following claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-108602

[0003]

Claims

[1] Battery management device (10) with a first measuring circuit (15) configured to measure a battery voltage of a lithium-ion secondary battery, a second measuring circuit (16) configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and to measure the amplitude of a resonant electrical signal, and an anomaly detection unit (23) configured to calculate the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and to detect an anomaly in the first measuring circuit (15) based on the calculated battery voltage. [2] Battery management device (10) according to claim 1, further comprising: an impedance measuring unit (21) configured to measure a real part of the impedance of the lithium-ion secondary battery based on a damping rate of the amplitude of the electrical signal, and a lithium detection unit (22) configured to detect, on the basis of the real part of the impedance, that Li has been deposited in the lithium-ion secondary battery. [3] Battery management device (10) according to claim 1 or 2, wherein the anomaly detection unit (23) calculates the battery voltage of the lithium-ion secondary battery on the basis of a resonant frequency of the electrical signal, the damping rate of the amplitude of the electrical signal and a phase difference. [4] Battery management device (10) according to claim 1 or 2, wherein the first and second measuring circuit (15, 16) are provided for each battery cell of the lithium-ion secondary battery. [5] Battery management device (10) according to claim 1 or 2, wherein the second measuring circuit (16) comprises a resonant circuit (41) configured to apply the high-frequency signal to the lithium-ion secondary battery, and a peak hold circuit (432) configured to measure the amplitude of the electrical signal. [6] Battery management procedures, including: Measuring the battery voltage of a lithium-ion secondary battery using a first measuring circuit (15), Applying a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and measuring the amplitude of a resonant electrical signal, and Calculating the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and detecting an anomaly in the first measuring circuit (15) based on the calculated battery voltage. [7] Program for a battery management device (10), wherein the battery management device (10) comprises: a first measuring circuit (15) configured to measure a battery voltage of a lithium-ion secondary battery, and a second measuring circuit (16) configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and to measure the amplitude of a resonant electrical signal, wherein the program is configured to cause the battery management device (10) to perform a process to calculate the battery voltage of the lithium-ion secondary battery from the amplitude of the electrical signal and to detect an anomaly in the first measuring circuit (15) based on the calculated battery voltage.

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