WO2015166926A1 - Lithium ion secondary battery system, and deterioration diagnosis method for lithium ion secondary battery - Google Patents

Lithium ion secondary battery system, and deterioration diagnosis method for lithium ion secondary battery Download PDF

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Publication number
WO2015166926A1
WO2015166926A1 PCT/JP2015/062731 JP2015062731W WO2015166926A1 WO 2015166926 A1 WO2015166926 A1 WO 2015166926A1 JP 2015062731 W JP2015062731 W JP 2015062731W WO 2015166926 A1 WO2015166926 A1 WO 2015166926A1
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Prior art keywords
lithium ion
secondary battery
ion secondary
battery
current
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PCT/JP2015/062731
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French (fr)
Japanese (ja)
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井上　亮
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株式会社日立製作所
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a lithium ion secondary battery system and a deterioration diagnosis method for a lithium ion secondary battery.
  • Hybrid electric vehicles require a strong assist force to assist the motor's acceleration force with a motor drive. For this reason, it is required to increase the output of a battery serving as a power source. Further, when the vehicle is running, depending on the control method of the hybrid system, charging and discharging of the battery with a large current having a maximum current value of 10C or more is repeated instantaneously. High output performance is required to be maintained even under such usage conditions.
  • a deterioration phenomenon in which the internal resistance of the battery gradually increases due to a charge / discharge cycle.
  • Such a deterioration phenomenon is likely to occur in the case of a charge / discharge cycle having a large current and a large capacity, and is further likely to occur by performing a charge / discharge cycle in a low temperature environment.
  • the above-described deterioration phenomenon depends on the environmental temperature and current. Since the input / output of the lithium ion secondary battery changes according to the deterioration, it is necessary to appropriately detect the deterioration state and perform various controls.
  • Patent Documents 1 and 2 disclose inventions for grasping the state of a lithium ion secondary battery by detecting an acoustic emission signal (AE signal) generated from the inside of the lithium ion secondary battery.
  • AE signal acoustic emission signal
  • Patent Document 1 discloses an invention for determining whether a battery is in a charged state or a discharged state from a difference between an AE signal at the time of charging and an AE signal at the time of discharging.
  • the invention described in Patent Document 1 it is possible to determine the state of charge or discharge of the battery by detecting the AE signal.
  • the battery deterioration state SOH: State of health
  • SOH State of health
  • Patent Document 2 discloses an invention for determining a charge / discharge region of a negative electrode active material of a battery based on charge / discharge inflection point-signal generation information when an increase in AE signal is detected.
  • the charge / discharge region of the negative electrode active material can be appropriately detected by detecting the AE signal.
  • the battery deterioration state (SOH) has not been diagnosed by using the AE signal.
  • a lithium ion secondary battery system includes an AE sensor that detects an acoustic emission signal generated inside a lithium ion secondary battery during charging or discharging of the lithium ion secondary battery, and an acoustic AE parameter acquisition unit for acquiring AE parameters based on emission signals, AE cumulative parameter acquisition unit for accumulating AE parameters and acquiring AE cumulative parameters, and deterioration of lithium ion secondary battery based on AE cumulative parameters A battery deterioration diagnosis unit.
  • the method for diagnosing deterioration of a lithium ion secondary battery according to one aspect of the present invention is based on an acoustic emission signal generated inside the lithium ion secondary battery when the lithium ion secondary battery is charged or discharged by a computer.
  • the AE parameter is acquired, and the computer accumulates the AE parameter to obtain the AE accumulated parameter, and the computer diagnoses the deterioration of the lithium ion secondary battery based on the AE accumulated parameter.
  • deterioration of a lithium ion secondary battery can be easily diagnosed based on AE cumulative parameters (AE event cumulative number, AE event cumulative intensity) calculated from an AE signal generated inside the lithium ion secondary battery. be able to.
  • AE cumulative parameters AE event cumulative number, AE event cumulative intensity
  • the whole block diagram of a battery apparatus The block diagram of a battery module.
  • the system flow figure of the secondary battery system concerning a 1st embodiment.
  • the system flow figure of the secondary battery system concerning a 2nd embodiment.
  • the system flow figure of the secondary battery system concerning a 3rd embodiment.
  • the system flow figure of the secondary battery system concerning a 5th embodiment.
  • the system flow figure of the secondary battery system concerning a 6th embodiment.
  • FIG. 1 shows the configuration of the battery device 1000.
  • the lithium ion secondary battery system of this invention points out the structure remove
  • FIG. 1 shows the configuration of the battery device 1000.
  • the battery device 1000 includes a system controller 1500, a database unit 1700, and a plurality (N) of units 500, that is, units 500-1, 500-2,..., 500-N.
  • Each unit 500 includes a battery module 1200 having a plurality of unit cell group units 1250, a current detection unit 1100 that detects a charge / discharge current of the battery module 1200, a voltage detection unit 1300 that detects a voltage of the battery module 1200, and a battery A module controller 1400 for controlling the charge / discharge current of the module 1200 and a relay 1600 are provided.
  • the module controller 1400 receives commands from the system controller 1500 and communicates with the current detection unit 1100, the voltage detection unit 1300, the database unit 1700, the relay 1600, and the battery module 1200, and performs charge / discharge control of the unit 500.
  • the module controller 1400 for example, a microcomputer having a processor and a memory is used.
  • the module controller 1400 sets the battery voltage and temperature of the unit cell included in the battery module 1200, the current value flowing through the battery module 1200 transmitted from the current detection unit 1100, and the total voltage value of the battery module 1200 transmitted from the voltage detection unit 1300. Based on this, the state of the battery module 1200 is detected, for example, a deterioration diagnosis of the cell group 1230 described later is performed.
  • the result of the processing performed by the module controller 1400 is transmitted to the cell controller 1220 and the system controller 1500 described later.
  • the system controller 1500 communicates with a host controller such as an in-vehicle system as indicated by double-ended arrows at the bottom of the figure.
  • the system controller 1500 also communicates with the module controller 1400. Based on the communication information, the system controller 1500 issues a charge / discharge control command for the unit 500 to the module controller 1400 in the unit 500.
  • a microcomputer having a processor and a memory is used.
  • the database unit 1700 stores information (threshold value or characteristic map) related to battery characteristics of the single battery 1210 described later. Based on this information, a battery deterioration diagnosis is performed.
  • FIG. 2 shows the configuration of the battery module 1200.
  • the battery module 1200 includes a plurality (M pieces) of single battery group units 1250, that is, single battery group units 1250-1, ..., 1250-M.
  • the single cell group unit 1250 includes a single cell group 1230 and a cell controller 1220.
  • the cell group 1230 in the first cell group unit 1250 and the cell controller 1220 are denoted by reference numerals 1230-1 and 1220-1, respectively, and the cell group 1230 in the Mth cell group unit 1250 Reference numerals 1230-M and 1220-M are assigned to the cell controllers 1220, respectively.
  • the single cell group 1230 includes a plurality (L) of single cells 1210, that is, single cells 1210-1,... 1210-L.
  • the single battery 1210 is a lithium ion secondary battery.
  • the cells 1210 are connected in series, but may be connected in parallel or in series-parallel.
  • the cell controller 1220 operates by receiving power from the assigned unit cell group 1230, and monitors and controls the states of the plurality of unit cells 1210 constituting the unit cell group 1230.
  • the cell controller 1220 will be described later with reference to FIG.
  • FIG. 3 shows one of the cell group units 1250.
  • the cell controller 1220 will be described with reference to FIG.
  • the cell controller 1220 includes a voltage detection circuit 1221, a temperature detection unit 1222, an AE sensor 1226, an AE signal detection unit 1225, a control circuit 1223, and a signal input / output circuit 1224.
  • the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210.
  • the temperature detector 1222 measures the temperature of one of the plurality of unit cells 1210, in the figure, the unit cell 1210-L, and recognizes it as a representative value of the unit cell group 1230. Note that the temperature detector 1222 can also be configured to measure the temperature of each of the plurality of single cells 1210.
  • the AE sensor 1226 is in close contact with one of the plurality of unit cells 1210, in the figure, the unit cell 1210-L.
  • the AE sensor 1226 detects an AE signal generated in the single battery 1210-L and recognizes it as a representative value of the AE signal of the single battery group 1230.
  • an AE sensor may be provided in each of the plurality of unit cells 1210 and an AE signal generated in each unit cell 1210 may be measured.
  • the AE sensor 1226 and the single battery 1210-L may be connected via a metal or the like that easily transmits ultrasonic waves.
  • the AE signal detection unit 1225 measures the number of AE events based on the AE signal from the cell group 1230 detected by the AE sensor 1226.
  • the AE sensor used in this embodiment has a resonance frequency of 30 kHz and can measure AE events having a frequency of 30 kHz or higher.
  • the AE signal detection unit 1225 processes the AE signal S AE obtained by the AE sensor 1226 as follows. First, a range in which a signal having an amplitude equal to or greater than a predetermined threshold continues is regarded as one group. The number of waves that the group has is acquired as the number of AE events. In addition, the maximum amplitude in the group is acquired as the AE event intensity. In the present embodiment, the AE event intensity is not used for the deterioration diagnosis of the cell group 1230.
  • AE parameters The number of AE events and the AE event intensity obtained in this way are collectively referred to as “AE parameters”.
  • the cumulative number of AE events is obtained from the number of AE events
  • the cumulative AE event intensity is obtained from the AE event intensity.
  • the AE event accumulation number and the AE event accumulation intensity are collectively referred to as “AE accumulation parameter”.
  • the control circuit 1223 receives information on the voltage obtained by the voltage detection circuit 1221, the temperature obtained by the temperature detection unit 1222, and the number of AE events obtained by the AE signal detection unit 1225, and the module controller 1400 via the signal input / output circuit 1224. Send to.
  • the control circuit 1223 for example, a microcomputer having a processor and a memory is used.
  • FIG. 4 is a diagram showing the configuration of the module controller 1400.
  • the module controller 1400 includes an AE controller 1410 and a battery deterioration diagnosis unit 1420.
  • the AE controller 1410 and the battery deterioration diagnosis unit 1420 are realized by executing predetermined software in the module controller 1400 that is a microcomputer, for example.
  • the AE controller 1410 integrates the AE parameters obtained by the AE signal detection unit 1225 of the cell controller 1220 over time to obtain an AE accumulated parameter.
  • the AE controller 1410 integrates the number of AE events that are AE parameters over time, and obtains the AE event cumulative number that is an AE cumulative parameter.
  • FIG. 15 shows groups 1 to 3 obtained by the method shown in FIG. 14 and AE event numbers A1 to A3 and AE event intensities B1 to B3 corresponding to AE parameters.
  • the AE cumulative parameter the AE parameters for the groups included in the measurement period, in this case, the groups 1 to 3, are accumulated over time. That is, in FIG. 15, the cumulative number of AE events is A1 + A2 + A3, and the cumulative AE event intensity is B1 + B2 + B3.
  • the AE controller 1410 After obtaining the AE event accumulation number, the AE controller 1410 outputs the AE event accumulation number to the battery deterioration diagnosis unit 1420.
  • the battery deterioration diagnosis unit 1420 performs battery deterioration diagnosis of the battery cell group 1230 based on the AE event accumulation number which is an AE accumulation parameter.
  • the battery deterioration diagnosis unit 1420 determines that the battery module 1200 is charged / discharged, the battery deterioration diagnosis unit 1420 also plays a role of sending a command for the AE sensor 1226 to measure the AE signal to the cell controller 1220. Details will be described with reference to FIG.
  • FIG. 5 is a diagram illustrating a correspondence relationship between the cumulative number of AE events and changes in battery internal resistance.
  • the horizontal axis represents the cumulative number of AE events, and the vertical axis represents the change in battery internal resistance.
  • three show curves when charging and discharging at current rates 1 to 3, respectively.
  • Current rate 1 ⁇ current rate 2 ⁇ current rate 3 There is a big and small relationship.
  • the remaining one shows a curve when charging / discharging is performed at a mixed current rate indicating a general use state in which various current rates including current rates 1 to 3 are mixed.
  • the general usage state indicates, for example, a curve obtained when an average user drives when the secondary battery system according to the present invention is used for in-vehicle use. It is possible to increase the curve of the mixed current rate by examining the internal resistance change with respect to various usage states and creating a database.
  • the battery internal resistance change also increases as the cumulative number of AE events increases. Therefore, by adding the internal resistance change to the initial internal resistance, the internal resistance after aging can be calculated. It is defined that the secondary battery has deteriorated when the internal resistance exceeds a predetermined value, and the correspondence between the cumulative number of AE events and the change in internal resistance is obtained in advance through experiments and simulations, resulting in an internal resistance exceeding the predetermined value.
  • the AE event cumulative number is stored as a threshold value. In the present embodiment, threshold values corresponding to various current rates are calculated in advance and stored in the database unit 1700.
  • the above threshold can be set by the user based on various experiences.
  • the battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart illustrating the battery deterioration diagnosis according to this embodiment shown in FIG.
  • the flowchart of FIG. 6 shows the procedure of a program executed by the processor of the control circuit 1223 in the module controller 1400, the system controller 1500, or the cell controller 1220, for example.
  • Step 101 A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 102> When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
  • Step 104 In the AE controller 1410 of the module controller 1400, the number of AE events measured by the AE signal detection unit 1225 in step 103 is acquired from the cell controller 1220, and this is integrated over time to calculate the cumulative number of AE events.
  • Step 105 Whether or not the cumulative number of AE events calculated in step 104 is equal to or greater than a threshold value stored in advance in database unit 1700 is determined by battery deterioration diagnosis unit 1420. At this time, a current rate is obtained from the current of the unit cell 1210 obtained in step 102, and based on this current rate, which threshold value is selected from various threshold values for each current rate stored in the database unit 1700. Is used for determination. If a positive determination is made, the process proceeds to step 106, and if a negative determination is made, the process returns to step 102.
  • the battery deterioration diagnosis unit 1420 outputs a signal indicating that the cumulative number of AE events detected from the lithium ion secondary battery is equal to or greater than the threshold, that is, a signal indicating battery characteristic deterioration, to the cell controller 1220 or the module controller 1400. To do.
  • the lithium ion secondary battery system of the present embodiment includes an AE sensor that detects an acoustic emission signal (AE signal) generated inside the cell group 1230 or the cell 1210 when the battery module 1200 is charged or discharged. 1226, an AE signal detector 1225 that acquires the number of AE events that are AE parameters based on the AE signal, an AE controller 1410 that acquires the number of AE events that are AE cumulative parameters based on the number of AE events, and an AE event A battery deterioration diagnosis unit 1420 for diagnosing deterioration of the battery module 1200 based on the cumulative number. Thereby, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
  • AE signal acoustic emission signal
  • the battery deterioration diagnosis unit 1420 of the secondary battery system diagnoses the deterioration of the lithium ion secondary battery by comparing the AE event cumulative number that is the AE cumulative parameter and the threshold for deterioration determination. To do. For example, a threshold value for deterioration determination calculated in advance in an experiment is stored in the database unit 1700, and it can be determined that the secondary battery has deteriorated when the cumulative number of AE events exceeds the threshold value for deterioration determination. Therefore, it is possible to easily diagnose the deterioration of the battery module 1200.
  • the secondary battery system of the first embodiment further includes a current detection unit 1100 that detects the charge / discharge current of the battery module 1200. Further, the deterioration determination threshold value is calculated and stored corresponding to the current rate. When the secondary battery system repeats charging and discharging at a predetermined current rate, a threshold value corresponding to the detected current is read, and it is determined that the battery has deteriorated when the cumulative number of AE events exceeds the read threshold value. Therefore, the deterioration of the secondary battery can be accurately determined using the threshold value corresponding to the charge / discharge current rate of the secondary battery.
  • the battery deterioration determination threshold value corresponding to the mixed current rate is read from the database unit 1700, the battery deterioration determination according to the current rate is accurately performed based on the cumulative number of AE events even in the secondary battery system in which the charge / discharge current varies. be able to.
  • the internal resistance is calculated from the cumulative number of AE events and the current, and the deterioration is diagnosed when the internal resistance is a predetermined value or more. Therefore, the correspondence shown in FIG. 5 is created in advance and stored in the database unit 1700. In the description of the present embodiment, the description of the same parts as in the first embodiment will be omitted.
  • Step 201> A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 202> When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
  • Step 204> In the AE controller 1410 of the module controller 1400, the number of AE events measured by the AE signal detection unit 1225 in step 203 is acquired from the cell controller 1220, and this is integrated over time to calculate the cumulative number of AE events.
  • Step 205> In the battery deterioration diagnosis unit 1420, a correspondence relationship between the cumulative number of AE events calculated in step 204, the current rate, the cumulative number of AE events corresponding to the current rate stored in the database unit 1700 in advance, and the battery internal resistance change ( The battery internal resistance is obtained from (see FIG. 5).
  • Step 206> When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400.
  • the lithium ion secondary battery system of this embodiment further includes a current detection unit 1100 that detects the current of the battery module 1200 (single cell group 1230, single cell 1210), and the battery deterioration diagnosis unit 1420 is an AE cumulative parameter.
  • the internal resistance of the battery is calculated by referring to the correspondence of FIG. 5 based on the cumulative number of AE events and the detected current value.
  • the battery internal resistance is equal to or higher than a predetermined value, it is diagnosed that the lithium ion secondary battery is deteriorated. Accordingly, as in the first embodiment, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
  • FIG. 8 is a diagram showing a correspondence relationship between the AE event cumulative intensity and the battery internal resistance change.
  • the horizontal axis represents the AE event cumulative intensity
  • the vertical axis represents the change in battery internal resistance.
  • three show curves when charging and discharging at current rates 1 to 3, respectively.
  • Current rate 1 ⁇ current rate 2 ⁇ current rate 3 There is a big and small relationship.
  • the remaining one shows a curve when charging / discharging is performed at a mixed current rate indicating a general use state in which various current rates including current rates 1 to 3 are mixed.
  • the general usage state indicates, for example, a curve obtained when an average user operates when the secondary battery system according to the present invention is used for in-vehicle use. It is possible to increase the curve of the mixed current rate by examining the internal resistance change with respect to various usage states and creating a database.
  • the battery internal resistance change increases as the AE event cumulative intensity increases. Therefore, by adding the internal resistance change to the initial internal resistance, the internal resistance after aging can be calculated. It is defined that the secondary battery has deteriorated when the internal resistance exceeds a predetermined value, and the correlation between the AE event cumulative intensity and the internal resistance change is obtained in advance by experiments and simulations, and the internal resistance becomes a predetermined value or more.
  • the AE event cumulative intensity is stored as a threshold value. In the present embodiment, threshold values corresponding to various current rates are calculated in advance and stored in the database unit 1700.
  • Step 301> A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 302> When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • Step 303> Based on the current and battery voltage of each single battery 1210 obtained in step 302, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
  • Step 304> In the AE controller 1410 of the module controller 1400, the AE event intensity measured by the AE signal detection unit 1225 in step 303 is acquired from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
  • the battery deterioration diagnosis unit 1420 determines whether or not the AE event cumulative intensity calculated in step 304 is equal to or greater than a threshold value stored in the database unit 1700 in advance. At this time, a current rate is obtained from the current of the unit cell 1210 obtained in step 302, and based on this current rate, which threshold value is selected from various threshold values for each current rate stored in the database unit 1700. Is used for determination. If a positive determination is made, the process proceeds to step 306, and if a negative determination is made, the process returns to step 302.
  • the battery deterioration diagnosis unit 1420 outputs a signal indicating that the AE event cumulative intensity detected from the lithium ion secondary battery is equal to or greater than the threshold value to the cell controller 1220 or the module controller 1400.
  • Step 401> A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 402> When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • Step 403> Based on the current and battery voltage of each single battery 1210 obtained in step 402, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
  • Step 404> In the AE controller 1410 of the module controller 1400, the AE event intensity measured by the AE signal detection unit 1225 in step 403 is acquired from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
  • Step 405 In battery deterioration diagnosis unit 1420, the correspondence relationship between the AE event cumulative intensity calculated in step 404, the current rate, the AE event cumulative intensity corresponding to the current rate stored in advance in database unit 1700, and the battery internal resistance change ( The internal resistance of the battery is obtained from (see FIG. 8).
  • Step 406> When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400.
  • the lithium ion secondary battery system in this embodiment includes a module controller 1400A shown in FIG. 11 instead of the module controller 1400 shown in FIG.
  • the module controller 1400A includes an AE controller 1410, a battery deterioration diagnosis unit 1420, and a current limit value calculation unit 1430.
  • the AE controller 1410, the battery deterioration diagnosis unit 1420, and the current limit value calculation unit 1430 are realized by executing predetermined software in the module controller 1400A, which is a microcomputer, for example.
  • the battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart of the battery deterioration diagnosis according to this embodiment shown in FIG.
  • Step 501> A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 502> When the cell controller 1220 receives a signal from the module controller 1400A, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The temperature detection unit 1222 measures the temperature of the cell group 1230. The control circuit 1223 receives measurement results from the voltage detection circuit 1221 and the temperature detection unit 1222 and transmits the measurement results to the module controller 1400A via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400A. The module controller 1400A converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • Step 503 Based on the current and battery voltage of each single battery 1210 obtained in step 502, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
  • Step 504 In the AE controller 1410 of the module controller 1400A, the number of AE events measured by the AE signal detection unit 1225 in step 503 is acquired from the cell controller 1220, and this is integrated with time to calculate the cumulative number of AE events.
  • Step 505 In the battery deterioration diagnosis unit 1420, the correspondence relationship between the cumulative number of AE events calculated in step 504, the current rate, the cumulative number of AE events corresponding to the current rate stored in advance in the database unit 1700, and the battery internal resistance change ( The battery internal resistance is obtained from (see FIG. 5).
  • Step 506> When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400A.
  • the current limit value calculation unit 1430 uses the battery voltage and temperature from the battery internal resistance obtained from the relationship between the cumulative number of AE events and the change in battery internal resistance to limit as follows. Calculate the current value. Assuming that the limited charging current value is Icmax and the limited discharging current value is Idmax, Icmax and Idmax are calculated by the following (Formula 1) and (Formula 2), respectively. In (Equation 1) and (Equation 2), R1 is the battery internal resistance obtained from the cumulative number of AE events, Vmax is the upper limit voltage of the unit cell 1210, Vmin is the lower limit voltage of the unit cell 1210, and OCV is the open state of the unit cell 1210.
  • the OCV is obtained by subtracting the voltage change due to the internal resistance from the battery voltage obtained in step 502.
  • Icmax (Vmax ⁇ OCV) / R1 (Formula 1)
  • Idmax (OCV ⁇ Vmin) / R1 (Formula 2)
  • the battery internal resistance R1 in (Expression 1) and (Expression 2) is calculated from the battery voltage, current, temperature, and time. The tendency of the increase rate of the internal resistance with respect to the charge / discharge cycle varies greatly depending on the environmental temperature. Therefore, it is desirable to appropriately set a limit value that is a threshold value of the internal resistance in accordance with a temperature change.
  • Step 508> The calculation result of the charge / discharge current limit value calculated by the current limit value calculation unit 1430 of the module controller 1400A is transmitted to the cell controller 1220 and the system controller 1500. Based on information from module controller 1400A, system controller 1500 sets the charging / discharging current value of each unit cell 1210 to be smaller than the value before it is determined in step 506 that the battery has deteriorated.
  • the lithium ion secondary battery system of the present embodiment further includes a limit current value calculation unit 1430 that calculates a limit current value of the battery module 1200 based on the battery internal resistance, and the battery current is calculated based on the limit current value. Restrict. Thereby, rapid battery deterioration can be suppressed, and input / output current can be appropriately controlled.
  • the lithium ion secondary battery system in this embodiment includes a module controller 1400A shown in FIG. 11 instead of the module controller 1400 shown in FIG.
  • the present embodiment is the same as the fifth embodiment except that the AE parameter is the AE event strength and the AE cumulative parameter is the AE event cumulative strength.
  • the description of the same parts as those in the first and fifth embodiments will be omitted.
  • the battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart of battery deterioration diagnosis according to this embodiment shown in FIG.
  • a signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
  • Step 602> When the cell controller 1220 receives a signal from the module controller 1400A, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The temperature detection unit 1222 measures the temperature of the cell group 1230. The control circuit 1223 receives measurement results from the voltage detection circuit 1221 and the temperature detection unit 1222 and transmits the measurement results to the module controller 1400A via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
  • Step 603> Based on the current and battery voltage of each cell 1210 obtained in step 602, battery deterioration diagnosis unit 1420 determines whether or not each cell 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
  • Step 604 In the AE controller 1410 of the module controller 1400A, the AE event intensity measured by the AE signal detection unit 1225 in step 603 is obtained from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
  • Step 605 In the battery deterioration diagnosis unit 1420, a correspondence relationship between the AE event cumulative intensity calculated in step 604, the current rate, the AE event cumulative intensity corresponding to the current rate stored in the database unit 1700 in advance, and the battery internal resistance change ( The internal resistance of the battery is obtained from (see FIG. 8).
  • Step 606 When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400A.
  • the current limit value calculation unit 1430 limits the battery voltage and temperature from the battery internal resistance obtained from the relationship between the AE event cumulative intensity and the battery internal resistance change as follows. Calculate the current value. Assuming that the limited charging current value is Icmax and the limited discharging current value is Idmax, Icmax and Idmax are calculated by the following (Equation 3) and (Equation 4), respectively. In (Equation 3) and (Equation 4), R2 is the battery internal resistance obtained from the AE event cumulative intensity, Vmax is the upper limit voltage of the unit cell 1210, Vmin is the lower limit voltage of the unit cell 1210, and OCV is the open state of the unit cell 1210. Circuit voltage.
  • the OCV is obtained by subtracting the voltage change due to the internal resistance from the battery voltage obtained in step 602.
  • Icmax (Vmax ⁇ OCV) / R2 (Formula 3)
  • Idmax (OCV ⁇ Vmin) / R2 (Formula 4)
  • the battery internal resistance R2 in (Expression 3) and (Expression 4) is calculated from the battery voltage, current, temperature, and time. The tendency of the increase rate of the internal resistance with respect to the charge / discharge cycle varies greatly depending on the environmental temperature. Therefore, it is desirable to appropriately set a limit value that is a threshold value of the internal resistance in accordance with a temperature change.
  • Step 608> The calculation result of the charge / discharge current limit value calculated by the current limit value calculation unit 1430 of the module controller 1400A is transmitted to the cell controller 1220 and the system controller 1500. Based on the information of module controller 1400A, system controller 1500 makes the charging / discharging current value of each single battery 1210 smaller than the charging / discharging current value before it is determined in step 606 that the battery has deteriorated.
  • the deterioration diagnosis of the lithium ion secondary battery can be performed by the following procedures (A) to (C) using the module controller 1400 which is a computer.
  • (A) When the battery module 1200 is charged or discharged by the AE controller 1410 of the module controller 1400, an acoustic emission signal (AE) generated inside the single cell group 1230 or the single cell 1210 and detected by the AE sensor 1226 The AE event number and the AE event intensity, which are AE parameters based on the signal), are acquired from the AE signal detection unit 1225.
  • AE acoustic emission signal
  • Steps 104, 204, 304, 404, 504, 604 (B) The AE controller 1410 of the module controller 1400 acquires the AE event cumulative number and the AE event cumulative strength, which are AE cumulative parameters, based on the acquired AE parameters. (Steps 104, 204, 304, 404, 504, 604) (C) The battery deterioration diagnosis unit 1420 of the module controller 1400 diagnoses deterioration of the battery module 1200 based on the AE cumulative parameter. Since the internal resistance varies depending on the temperature, the above-described deterioration diagnosis is performed in consideration of the temperature measured by the temperature detection unit 1222. (Steps 105, 206, 305, 406, 506, 606)
  • the amplitude of the AE signal (AE generation intensity) is approximated (linear approximation) as a linear function of the charge / discharge current, and the cycle number of the lithium ion secondary battery is calculated from the slope and intercept. Therefore, an invention for diagnosing deterioration of a lithium ion secondary battery is disclosed. In the invention, the number of cycles can be estimated, but the battery deterioration state (SOH) has not been diagnosed.
  • the present invention since the present invention only accumulates the AE parameters such as the number of AE events and the AE event intensity, the battery deterioration state (SOH) can be easily diagnosed.
  • SOHR Internal Resistance Degradation Index
  • Japanese Unexamined Patent Application Publication No. 2013-187031 discloses an invention that outputs a signal indicating deterioration when the number of AE events occurring in one charge / discharge cycle is equal to or greater than a threshold value.
  • the number of AE events is obtained from one AE event, and this is used as a criterion for deterioration.
  • Obtaining the number of AE events from one AE event is greatly affected by erroneous measurement due to temporary noise or the like.
  • the said invention has not led to a battery deterioration state (SOH) diagnosis.
  • SOH battery deterioration state
  • the battery deterioration state is diagnosed using an AE cumulative parameter (AE event cumulative number or AE event cumulative strength) obtained by accumulating AE parameters such as the number of AE events and the AE event strength. . Therefore, even if some erroneous measurement values are included, most of them are accurate measurement values and thus are not greatly affected. Further, the battery deterioration state (SOH, strictly speaking, SOHR) can be diagnosed by using the AE accumulation parameter (AE event accumulation number or AE event accumulation intensity).
  • AE cumulative parameter AE event cumulative number or AE event cumulative strength
  • the present invention relates to a secondary battery control circuit of a secondary battery device that constitutes a power source of an industrial vehicle such as a passenger car such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (EV) or a hybrid railway vehicle. Applicable.
  • an industrial vehicle such as a passenger car
  • a hybrid vehicle (HEV) such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (EV) or a hybrid railway vehicle.
  • HEV hybrid vehicle
  • PHEV plug-in hybrid vehicle
  • EV electric vehicle
  • Battery device 1100 Current detection unit 1200: Battery module 1210: Single battery 1220: Cell controller 1221: Voltage detection circuit 1222: Temperature detector 1223: Control circuit 1224: Signal input / output circuit 1225: AE signal detection unit 1226: AE sensor 1230: single cell group 1300: Voltage detector 1400, 1400A: Module controller 1410: AE controller 1420: Battery deterioration diagnosis unit 1430: Current limit value calculation unit 1500: System controller 1600: Relay 1700: Database section

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Abstract

A lithium ion secondary battery system is provided with: an AE sensor for detecting an acoustic emission signal generated in a lithium ion secondary battery when the lithium ion secondary battery is charged or discharged; an AE parameter acquisition unit for acquiring an AE parameter on the basis of the acoustic emission signal; an AE cumulative parameter acquisition unit for acquiring an AE cumulative parameter by accumulating the AE parameters; and a battery deterioration diagnosis unit for diagnosing deterioration of the lithium ion secondary battery on the basis of the AE cumulative parameter.

Description

リチウムイオン二次電池システム、および、リチウムイオン二次電池の劣化診断方法Lithium ion secondary battery system and degradation diagnosis method for lithium ion secondary battery
　本発明は、リチウムイオン二次電池システム、および、リチウムイオン二次電池の劣化診断方法に関する。 The present invention relates to a lithium ion secondary battery system and a deterioration diagnosis method for a lithium ion secondary battery.
　ハイブリッド電気自動車においては、自動車の加速力をモータ駆動でアシストするために強力なアシスト力を必要とする。そのため、電源となる電池の高出力化が要求されている。また、車両走行時では、ハイブリッドシステムの制御方法にもよるが、電池は最大電流値が時間率１０Ｃ以上に及ぶ大電流での充電および放電が瞬時に連続的に繰り返される。このような使用条件においても高出力性能が維持されることが求められている。 Hybrid electric vehicles require a strong assist force to assist the motor's acceleration force with a motor drive. For this reason, it is required to increase the output of a battery serving as a power source. Further, when the vehicle is running, depending on the control method of the hybrid system, charging and discharging of the battery with a large current having a maximum current value of 10C or more is repeated instantaneously. High output performance is required to be maintained even under such usage conditions.
　このようなリチウムイオン二次電池を用いた二次電池システムでは充放電サイクルによって電池の内部抵抗が徐々に増大する劣化現象が知られている。このような劣化現象は、大電流大容量な充放電サイクルの場合に発生し易く、さらに低温環境において充放電サイクルをすることにより、更に発生し易くなる。このように、上述の劣化現象は環境温度や電流に依存している。リチウムイオン二次電池の入出力は劣化に応じて変化するので劣化状態を適切に検出し、種々の制御を行う必要がある。 In such a secondary battery system using a lithium ion secondary battery, a deterioration phenomenon is known in which the internal resistance of the battery gradually increases due to a charge / discharge cycle. Such a deterioration phenomenon is likely to occur in the case of a charge / discharge cycle having a large current and a large capacity, and is further likely to occur by performing a charge / discharge cycle in a low temperature environment. Thus, the above-described deterioration phenomenon depends on the environmental temperature and current. Since the input / output of the lithium ion secondary battery changes according to the deterioration, it is necessary to appropriately detect the deterioration state and perform various controls.
　特許文献１、２には、リチウムイオン二次電池内部から発生するアコースティックエミッション信号（ＡＥ信号）を検出することでリチウムイオン二次電池の状態を把握する発明が開示されている。 Patent Documents 1 and 2 disclose inventions for grasping the state of a lithium ion secondary battery by detecting an acoustic emission signal (AE signal) generated from the inside of the lithium ion secondary battery.
　特許文献１には、充電時におけるＡＥ信号と放電時におけるＡＥ信号の差異から電池が充電状態および放電状態のいずれであるかを判断する発明が開示されている。特許文献１に記載の発明では、ＡＥ信号を検出することにより、電池の充電状態、もしくは放電状態を判断することは可能である。しかしながら、ＡＥ信号を使用することにより電池劣化状態（ＳＯＨ：Ｓｔａｔｅ　ｏｆ　ｈｅａｌｔｈ）を診断するに至っていない。 Patent Document 1 discloses an invention for determining whether a battery is in a charged state or a discharged state from a difference between an AE signal at the time of charging and an AE signal at the time of discharging. In the invention described in Patent Document 1, it is possible to determine the state of charge or discharge of the battery by detecting the AE signal. However, the battery deterioration state (SOH: State of health) has not been diagnosed by using the AE signal.
　特許文献２には、ＡＥ信号の増大を検出した場合に、充放電変曲点－信号発生情報に基づいて電池の負極活物質の充放電領域を判断する発明が開示されている。特許文献２に記載の発明では、ＡＥ信号を検出することにより、負極活物質の充放電領域を適切に検出可能である。しかしながら、特許文献１と同様に、ＡＥ信号を使用することにより電池劣化状態（ＳＯＨ）を診断するに至っていない。 Patent Document 2 discloses an invention for determining a charge / discharge region of a negative electrode active material of a battery based on charge / discharge inflection point-signal generation information when an increase in AE signal is detected. In the invention described in Patent Document 2, the charge / discharge region of the negative electrode active material can be appropriately detected by detecting the AE signal. However, as in Patent Document 1, the battery deterioration state (SOH) has not been diagnosed by using the AE signal.
日本国特開２０１３－１１３８３１号公報Japanese Unexamined Patent Publication No. 2013-113831 日本国特開２０１３－０８９４２３号公報Japanese Unexamined Patent Publication No. 2013-089423
　このように、リチウムイオン二次電池の劣化を診断するリチウムイオン二次電池システムが望まれていた。 Thus, a lithium ion secondary battery system for diagnosing deterioration of a lithium ion secondary battery has been desired.
（１）本発明の一態様によるリチウムイオン二次電池システムは、リチウムイオン二次電池の充電時または放電時に、リチウムイオン二次電池の内部で発生したアコースティックエミッション信号を検出するＡＥセンサと、アコースティックエミッション信号に基づいてＡＥパラメータを取得するＡＥパラメータ取得部と、ＡＥパラメータを累積して、ＡＥ累積パラメータを取得するＡＥ累積パラメータ取得部と、ＡＥ累積パラメータに基づいて、リチウムイオン二次電池の劣化を診断する電池劣化診断部と、を備える。
（２）本発明の一態様によるリチウムイオン二次電池の劣化診断方法は、コンピュータにより、リチウムイオン二次電池の充電時または放電時にリチウムイオン二次電池の内部で発生したアコースティックエミッション信号に基づいたＡＥパラメータを取得し、コンピュータにより、ＡＥパラメータを累積してＡＥ累積パラメータを取得し、コンピュータにより、ＡＥ累積パラメータに基づいて、リチウムイオン二次電池の劣化を診断する。 (1) A lithium ion secondary battery system according to an aspect of the present invention includes an AE sensor that detects an acoustic emission signal generated inside a lithium ion secondary battery during charging or discharging of the lithium ion secondary battery, and an acoustic AE parameter acquisition unit for acquiring AE parameters based on emission signals, AE cumulative parameter acquisition unit for accumulating AE parameters and acquiring AE cumulative parameters, and deterioration of lithium ion secondary battery based on AE cumulative parameters A battery deterioration diagnosis unit.
(2) The method for diagnosing deterioration of a lithium ion secondary battery according to one aspect of the present invention is based on an acoustic emission signal generated inside the lithium ion secondary battery when the lithium ion secondary battery is charged or discharged by a computer. The AE parameter is acquired, and the computer accumulates the AE parameter to obtain the AE accumulated parameter, and the computer diagnoses the deterioration of the lithium ion secondary battery based on the AE accumulated parameter.
　本発明により、リチウムイオン二次電池の内部で発生したＡＥ信号から算出されたＡＥ累積パラメータ（ＡＥ事象累積数、ＡＥ事象累積強度）に基づいて、リチウムイオン二次電池の劣化を簡便に診断することができる。 According to the present invention, deterioration of a lithium ion secondary battery can be easily diagnosed based on AE cumulative parameters (AE event cumulative number, AE event cumulative intensity) calculated from an AE signal generated inside the lithium ion secondary battery. be able to.
電池装置の全体構成図。The whole block diagram of a battery apparatus. 電池モジュールの構成図。The block diagram of a battery module. セルコントローラの回路構成を示す図。The figure which shows the circuit structure of a cell controller. 第１～第４実施形態に係るモジュールコントローラの回路構成を示す図。The figure which shows the circuit structure of the module controller which concerns on 1st-4th embodiment. ＡＥ事象累積数と電池内部抵抗変化の対応関係を示す図。The figure which shows the correspondence of AE event accumulation number and battery internal resistance change. 第１実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 1st embodiment. 第２実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 2nd embodiment. ＡＥ事象累積強度と電池内部抵抗変化の対応関係を示す図。The figure which shows the correspondence of AE event accumulation intensity and battery internal resistance change. 第３実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 3rd embodiment. 第４実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 4th embodiment. 第５及び第６実施形態に係るモジュールコントローラの回路構成を示す図。The figure which shows the circuit structure of the module controller which concerns on 5th and 6th embodiment. 第５実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 5th embodiment. 第６実施形態に係る二次電池システムのシステムフロー図。The system flow figure of the secondary battery system concerning a 6th embodiment. ＡＥ事象数及びＡＥ事象強度を説明する図。The figure explaining the number of AE events and AE event intensity. ＡＥ事象累積数及びＡＥ事象累積強度を説明する図。The figure explaining the AE event accumulation number and AE event accumulation intensity.
―第１実施形態―
　図１は、電池装置１０００の構成を示している。なお、本発明のリチウムイオン二次電池システムは、電池装置１０００から少なくともリチウムイオン二次電池を除いた構成を指す。 -First embodiment-
FIG. 1 shows the configuration of the battery device 1000. In addition, the lithium ion secondary battery system of this invention points out the structure remove | excluding at least a lithium ion secondary battery from the battery apparatus 1000. FIG.
　電池装置１０００は、システムコントローラ１５００と、データベース部１７００と、複数（Ｎ個）のユニット５００、すなわち、ユニット５００－１、５００－２、・・・、５００－Ｎとを有する。 The battery device 1000 includes a system controller 1500, a database unit 1700, and a plurality (N) of units 500, that is, units 500-1, 500-2,..., 500-N.
　各々のユニット５００は、単電池群ユニット１２５０を複数有する電池モジュール１２００と、電池モジュール１２００の充放電電流を検出する電流検出部１１００と、電池モジュール１２００の電圧を検出する電圧検出部１３００と、電池モジュール１２００の充放電電流を制御するモジュールコントローラ１４００と、リレー１６００と、を有する。 Each unit 500 includes a battery module 1200 having a plurality of unit cell group units 1250, a current detection unit 1100 that detects a charge / discharge current of the battery module 1200, a voltage detection unit 1300 that detects a voltage of the battery module 1200, and a battery A module controller 1400 for controlling the charge / discharge current of the module 1200 and a relay 1600 are provided.
　モジュールコントローラ１４００は、システムコントローラ１５００の指令を受けて、電流検出部１１００、電圧検出部１３００、データベース部１７００、リレー１６００、及び、電池モジュール１２００と通信し、ユニット５００の充放電制御を行う。モジュールコントローラ１４００には、たとえばプロセッサとメモリを有するマイクロコンピュータが用いられる。 The module controller 1400 receives commands from the system controller 1500 and communicates with the current detection unit 1100, the voltage detection unit 1300, the database unit 1700, the relay 1600, and the battery module 1200, and performs charge / discharge control of the unit 500. As the module controller 1400, for example, a microcomputer having a processor and a memory is used.
　モジュールコントローラ１４００は、電池モジュール１２００が有する単電池の電池電圧や温度、電流検出部１１００から送信される電池モジュール１２００に流れる電流値、電圧検出部１３００から送信される電池モジュール１２００の総電圧値に基づいて電池モジュール１２００の状態検出、例えば後述する単電池群１２３０の劣化診断などを行う。 The module controller 1400 sets the battery voltage and temperature of the unit cell included in the battery module 1200, the current value flowing through the battery module 1200 transmitted from the current detection unit 1100, and the total voltage value of the battery module 1200 transmitted from the voltage detection unit 1300. Based on this, the state of the battery module 1200 is detected, for example, a deterioration diagnosis of the cell group 1230 described later is performed.
　また、モジュールコントローラ１４００が行う処理の結果は、後述するセルコントローラ１２２０やシステムコントローラ１５００に送信される。 Also, the result of the processing performed by the module controller 1400 is transmitted to the cell controller 1220 and the system controller 1500 described later.
　システムコントローラ１５００は、図示下方の両端矢印で示すように車載システムなどの上位コントローラと通信する。また、システムコントローラ１５００は、モジュールコントローラ１４００とも通信する。それらの通信情報に基づいて、システムコントローラ１５００は、ユニット５００内のモジュールコントローラ１４００に、ユニット５００の充放電制御の指令を出す。システムコントローラ１５００には、たとえばプロセッサとメモリを有するマイクロコンピュータが用いられる。 The system controller 1500 communicates with a host controller such as an in-vehicle system as indicated by double-ended arrows at the bottom of the figure. The system controller 1500 also communicates with the module controller 1400. Based on the communication information, the system controller 1500 issues a charge / discharge control command for the unit 500 to the module controller 1400 in the unit 500. For the system controller 1500, for example, a microcomputer having a processor and a memory is used.
　データベース部１７００は、後述する単電池１２１０の電池特性に関する情報（閾値または特性マップ）を格納する。この情報に基づいて電池劣化診断が行われる。 The database unit 1700 stores information (threshold value or characteristic map) related to battery characteristics of the single battery 1210 described later. Based on this information, a battery deterioration diagnosis is performed.
　図２は、電池モジュール１２００の構成を示している。図２に示すように、電池モジュール１２００は、複数（Ｍ個）の単電池群ユニット１２５０、すなわち、単電池群ユニット１２５０－１、・・・、１２５０－Ｍを有する。 FIG. 2 shows the configuration of the battery module 1200. As shown in FIG. 2, the battery module 1200 includes a plurality (M pieces) of single battery group units 1250, that is, single battery group units 1250-1, ..., 1250-M.
　単電池群ユニット１２５０は、単電池群１２３０とセルコントローラ１２２０を有する。なお、１番目の単電池群ユニット１２５０内の単電池群１２３０とセルコントローラ１２２０には符号１２３０－１、１２２０－１をそれぞれ付し、Ｍ番目の単電池群ユニット１２５０内の単電池群１２３０とセルコントローラ１２２０には符号１２３０－Ｍ、１２２０－Ｍをそれぞれ付した。 The single cell group unit 1250 includes a single cell group 1230 and a cell controller 1220. The cell group 1230 in the first cell group unit 1250 and the cell controller 1220 are denoted by reference numerals 1230-1 and 1220-1, respectively, and the cell group 1230 in the Mth cell group unit 1250 Reference numerals 1230-M and 1220-M are assigned to the cell controllers 1220, respectively.
　単電池群１２３０は、複数（Ｌ個）の単電池１２１０、すなわち、単電池１２１０－１、・・・１２１０－Ｌを有する。単電池１２１０は、リチウムイオン二次電池である。図では、単電池１２１０同士を直列で接続しているが並列や直並列などで接続してもよい。 The single cell group 1230 includes a plurality (L) of single cells 1210, that is, single cells 1210-1,... 1210-L. The single battery 1210 is a lithium ion secondary battery. In the figure, the cells 1210 are connected in series, but may be connected in parallel or in series-parallel.
　セルコントローラ１２２０は割り当てられた単電池群１２３０からの電力を受けて動作し、単電池群１２３０を構成する複数の単電池１２１０の状態を監視及び制御する。セルコントローラ１２２０については図３を用いて後述する。 The cell controller 1220 operates by receiving power from the assigned unit cell group 1230, and monitors and controls the states of the plurality of unit cells 1210 constituting the unit cell group 1230. The cell controller 1220 will be described later with reference to FIG.
　図３は、単電池群ユニット１２５０の１つを示している。図３を用いて、セルコントローラ１２２０について説明する。 FIG. 3 shows one of the cell group units 1250. The cell controller 1220 will be described with reference to FIG.
　セルコントローラ１２２０は、電圧検出回路１２２１、温度検出部１２２２、ＡＥセンサ１２２６、ＡＥ信号検出部１２２５、制御回路１２２３、信号入出力回路１２２４を備えている。 The cell controller 1220 includes a voltage detection circuit 1221, a temperature detection unit 1222, an AE sensor 1226, an AE signal detection unit 1225, a control circuit 1223, and a signal input / output circuit 1224.
　電圧検出回路１２２１は、各々の単電池１２１０の端子間電圧を測定する。 The voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210.
　温度検出部１２２２は、複数ある単電池１２１０のうちの１つ、図では、単電池１２１０－Ｌ、の温度を測定し、単電池群１２３０の代表値として認識する。なお、複数ある単電池１２１０のそれぞれの温度を温度検出部１２２２が測定するように構成することもできる。 The temperature detector 1222 measures the temperature of one of the plurality of unit cells 1210, in the figure, the unit cell 1210-L, and recognizes it as a representative value of the unit cell group 1230. Note that the temperature detector 1222 can also be configured to measure the temperature of each of the plurality of single cells 1210.
　ＡＥセンサ１２２６は、複数ある単電池１２１０のうちの１つ、図では、単電池１２１０－Ｌに密着している。そして、ＡＥセンサ１２２６は、単電池１２１０－Ｌ内で発生するＡＥ信号を検出し、それを単電池群１２３０のＡＥ信号の代表値として認識する。なお、ＡＥセンサを複数ある単電池１２１０のそれぞれに設け、単電池１２１０のそれぞれで発生するＡＥ信号を測定するようにすることもできる。また、単電池１２１０－ＬにＡＥセンサ１２２６を密着させにくい場合には、ＡＥセンサ１２２６と単電池１２１０－Ｌとを超音波が伝わりやすい金属等を介して接続してもよい。 The AE sensor 1226 is in close contact with one of the plurality of unit cells 1210, in the figure, the unit cell 1210-L. The AE sensor 1226 detects an AE signal generated in the single battery 1210-L and recognizes it as a representative value of the AE signal of the single battery group 1230. Note that an AE sensor may be provided in each of the plurality of unit cells 1210 and an AE signal generated in each unit cell 1210 may be measured. Further, when it is difficult to make the AE sensor 1226 in close contact with the single battery 1210-L, the AE sensor 1226 and the single battery 1210-L may be connected via a metal or the like that easily transmits ultrasonic waves.
　ＡＥ信号検出部１２２５は、ＡＥセンサ１２２６が検出した単電池群１２３０からのＡＥ信号に基づいてＡＥ事象数を測定する。本実施形態で使用しているＡＥセンサは共振周波数３０ｋＨｚであり、３０ｋＨｚ以上の周波数のＡＥ事象を測定可能である。 The AE signal detection unit 1225 measures the number of AE events based on the AE signal from the cell group 1230 detected by the AE sensor 1226. The AE sensor used in this embodiment has a resonance frequency of 30 kHz and can measure AE events having a frequency of 30 kHz or higher.
　ここで、図１４を用いて、ＡＥ信号検出部１２２５の動作について説明する。ＡＥ信号検出部１２２５は、ＡＥセンサ１２２６が得たＡＥ信号ＳＡＥを以下のように処理する。まず、所定のしきい値以上の振幅の信号が続く範囲を１つのグループと捉える。そのグループが有する波の数をＡＥ事象数として取得する。また、そのグループの中での最大振幅をＡＥ事象強度として取得する。なお、本実施形態においては、ＡＥ事象強度は単電池群１２３０の劣化診断には用いない。 Here, the operation of the AE signal detection unit 1225 will be described with reference to FIG. The AE signal detection unit 1225 processes the AE signal S AE obtained by the AE sensor 1226 as follows. First, a range in which a signal having an amplitude equal to or greater than a predetermined threshold continues is regarded as one group. The number of waves that the group has is acquired as the number of AE events. In addition, the maximum amplitude in the group is acquired as the AE event intensity. In the present embodiment, the AE event intensity is not used for the deterioration diagnosis of the cell group 1230.
　このようにして得られたＡＥ事象数とＡＥ事象強度を総称して、「ＡＥパラメータ」と呼ぶことにする。なお、後述するように、ＡＥ事象数からはＡＥ事象累積数が求められ、ＡＥ事象強度からはＡＥ事象累積強度が求められる。ＡＥ事象累積数とＡＥ事象累積強度を総称して、「ＡＥ累積パラメータ」と呼ぶことにする。 The number of AE events and the AE event intensity obtained in this way are collectively referred to as “AE parameters”. As will be described later, the cumulative number of AE events is obtained from the number of AE events, and the cumulative AE event intensity is obtained from the AE event intensity. The AE event accumulation number and the AE event accumulation intensity are collectively referred to as “AE accumulation parameter”.
　図３の説明に戻る。制御回路１２２３は、電圧検出回路１２２１が得た電圧、温度検出部１２２２が得た温度、ＡＥ信号検出部１２２５が得たＡＥ事象数の情報を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００に送信する。制御回路１２２３には、たとえばプロセッサとメモリを有するマイクロコンピュータが用いられる。 Returning to the explanation of FIG. The control circuit 1223 receives information on the voltage obtained by the voltage detection circuit 1221, the temperature obtained by the temperature detection unit 1222, and the number of AE events obtained by the AE signal detection unit 1225, and the module controller 1400 via the signal input / output circuit 1224. Send to. As the control circuit 1223, for example, a microcomputer having a processor and a memory is used.
　なお、セルコントローラ１２２０に一般的に実装される、自己放電や消費電流ばらつき等に伴い発生する単電池１２１０間の電圧ばらつきを均等化する回路構成は周知のものであり、記載を省略した。 Note that a circuit configuration that is generally mounted on the cell controller 1220 and that equalizes voltage variations between the single cells 1210 caused by variations in self-discharge and current consumption is well known, and the description is omitted.
　図４は、モジュールコントローラ１４００の構成を示す図である。モジュールコントローラ１４００は、ＡＥコントローラ１４１０と電池劣化診断部１４２０から構成される。ＡＥコントローラ１４１０と電池劣化診断部１４２０は、たとえばマイクロコンピュータであるモジュールコントローラ１４００において所定のソフトウェアを実行することにより、それぞれ実現される。 FIG. 4 is a diagram showing the configuration of the module controller 1400. The module controller 1400 includes an AE controller 1410 and a battery deterioration diagnosis unit 1420. The AE controller 1410 and the battery deterioration diagnosis unit 1420 are realized by executing predetermined software in the module controller 1400 that is a microcomputer, for example.
　ＡＥコントローラ１４１０は、セルコントローラ１２２０のＡＥ信号検出部１２２５で求められたＡＥパラメータを時間積算してＡＥ累積パラメータを求める。本実施形態では、ＡＥコントローラ１４１０は、ＡＥパラメータであるＡＥ事象数を時間積算して、ＡＥ累積パラメータであるＡＥ事象累積数を求める。 The AE controller 1410 integrates the AE parameters obtained by the AE signal detection unit 1225 of the cell controller 1220 over time to obtain an AE accumulated parameter. In the present embodiment, the AE controller 1410 integrates the number of AE events that are AE parameters over time, and obtains the AE event cumulative number that is an AE cumulative parameter.
　ここで、図１５を用いて、ＡＥ事象数からＡＥ事象累積数を、ＡＥ事象強度からＡＥ事象累積強度を求める方法について述べる。図１５には、図１４に示す方法で得られたグループ１～３とそれらに対応するＡＥパラメータであるＡＥ事象数Ａ１～Ａ３とＡＥ事象強度Ｂ１～Ｂ３が示されている。ＡＥ累積パラメータは、測定期間に含まれているグループ、ここでは、グループ１～３についてのＡＥパラメータを時間積算する。すなわち、図１５においては、ＡＥ事象累積数はＡ１＋Ａ２＋Ａ３となり、ＡＥ事象累積強度はＢ１＋Ｂ２＋Ｂ３となる。 Here, a method for obtaining the AE event cumulative number from the AE event number and the AE event cumulative strength from the AE event strength will be described with reference to FIG. FIG. 15 shows groups 1 to 3 obtained by the method shown in FIG. 14 and AE event numbers A1 to A3 and AE event intensities B1 to B3 corresponding to AE parameters. As the AE cumulative parameter, the AE parameters for the groups included in the measurement period, in this case, the groups 1 to 3, are accumulated over time. That is, in FIG. 15, the cumulative number of AE events is A1 + A2 + A3, and the cumulative AE event intensity is B1 + B2 + B3.
　図４の説明に戻る。ＡＥ事象累積数を求めた後、ＡＥコントローラ１４１０は、ＡＥ事象累積数を電池劣化診断部１４２０に出力する。 Returning to the explanation of FIG. After obtaining the AE event accumulation number, the AE controller 1410 outputs the AE event accumulation number to the battery deterioration diagnosis unit 1420.
　電池劣化診断部１４２０は、ＡＥ累積パラメータであるＡＥ事象累積数に基づいて単電池群１２３０の電池劣化診断を行う。 The battery deterioration diagnosis unit 1420 performs battery deterioration diagnosis of the battery cell group 1230 based on the AE event accumulation number which is an AE accumulation parameter.
　なお、電池劣化診断部１４２０は、電池モジュール１２００が充放電されていると判別すると、ＡＥセンサ１２２６がＡＥ信号を測定する指令をセルコントローラ１２２０に送る役割も担っている。詳細は、図５を用いて説明する。 Note that when the battery deterioration diagnosis unit 1420 determines that the battery module 1200 is charged / discharged, the battery deterioration diagnosis unit 1420 also plays a role of sending a command for the AE sensor 1226 to measure the AE signal to the cell controller 1220. Details will be described with reference to FIG.
　図５は、ＡＥ事象累積数と電池内部抵抗変化の対応関係を示す図である。横軸はＡＥ事象累積数、縦軸は電池内部抵抗の変化を示している。４本示されている曲線のうちの３本は、電流レート１～３でそれぞれ充放電したときの曲線を示している。なお、電流レート１～３において、
　電流レート１　＜　電流レート２　＜　電流レート３
という大小関係がある。 FIG. 5 is a diagram illustrating a correspondence relationship between the cumulative number of AE events and changes in battery internal resistance. The horizontal axis represents the cumulative number of AE events, and the vertical axis represents the change in battery internal resistance. Of the four curves shown, three show curves when charging and discharging at current rates 1 to 3, respectively. At current rates 1 to 3,
Current rate 1 <current rate 2 <current rate 3
There is a big and small relationship.
　残りの１本は、電流レート１～３なども含む様々な電流レートが混合した一般的な使用状態を示す混合電流レートで充放電を行ったときの曲線を示している。一般的な使用状態とは、例えば、本発明による二次電池システムが車載用として用いられるとき、平均的なユーザが運転した場合に得られる曲線を示している。なお、様々な使用状態に対する内部抵抗変化を調べてデータベース化することで混合電流レートの曲線を増やすことができる。 The remaining one shows a curve when charging / discharging is performed at a mixed current rate indicating a general use state in which various current rates including current rates 1 to 3 are mixed. The general usage state indicates, for example, a curve obtained when an average user drives when the secondary battery system according to the present invention is used for in-vehicle use. It is possible to increase the curve of the mixed current rate by examining the internal resistance change with respect to various usage states and creating a database.
　それぞれの電流レートにおいて、ＡＥ事象累積数が大きくなると電池内部抵抗変化も大きくなる。したがって、初期の内部抵抗に内部抵抗変化分を加算すると経年変化後の内部抵抗が算出できる。
　内部抵抗が所定値以上となったときに二次電池が劣化したと定義し、ＡＥ事象累積数と内部抵抗変化との対応関係を予め実験やシミュレーションにより求めて、所定値以上の内部抵抗となるＡＥ事象累積数を閾値として記憶する。本実施形態では、様々な電流レートに対応した閾値が予め算出されてデータベース部１７００に記憶されている。 At each current rate, the battery internal resistance change also increases as the cumulative number of AE events increases. Therefore, by adding the internal resistance change to the initial internal resistance, the internal resistance after aging can be calculated.
It is defined that the secondary battery has deteriorated when the internal resistance exceeds a predetermined value, and the correspondence between the cumulative number of AE events and the change in internal resistance is obtained in advance through experiments and simulations, resulting in an internal resistance exceeding the predetermined value. The AE event cumulative number is stored as a threshold value. In the present embodiment, threshold values corresponding to various current rates are calculated in advance and stored in the database unit 1700.
　なお、上述の閾値は、ユーザが各種経験をもとに、設定することも可能である。 Note that the above threshold can be set by the user based on various experiences.
　図６に示す本実施形態における電池劣化診断について説明したフロー図を用いて、本実施形態における電池劣化診断について説明する。図６のフロー図は、例えば、モジュールコントローラ１４００、システムコントローラ１５００、またはセルコントローラ１２２０内の制御回路１２２３のプロセッサで実行されるプログラムの手順を示すものである。 The battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart illustrating the battery deterioration diagnosis according to this embodiment shown in FIG. The flowchart of FIG. 6 shows the procedure of a program executed by the processor of the control circuit 1223 in the module controller 1400, the system controller 1500, or the cell controller 1220, for example.
＜ステップ１０１＞
　リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 101>
A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ１０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００からの信号を受信すると、電圧検出回路１２２１は、各単電池１２１０の端子間電圧を測定する。制御回路１２２３は、電圧検出回路１２２１の測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００に送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００に送信する。モジュールコントローラ１４００は、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 102>
When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
＜ステップ１０３＞
　ステップ１０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象数が測定される。 <Step 103>
Based on the current and battery voltage of each single battery 1210 obtained in step 102, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
＜ステップ１０４＞
　モジュールコントローラ１４００のＡＥコントローラ１４１０において、ステップ１０３でＡＥ信号検出部１２２５により測定されたＡＥ事象数をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積数を演算する。 <Step 104>
In the AE controller 1410 of the module controller 1400, the number of AE events measured by the AE signal detection unit 1225 in step 103 is acquired from the cell controller 1220, and this is integrated over time to calculate the cumulative number of AE events.
＜ステップ１０５＞
　ステップ１０４で演算されたＡＥ事象累積数が、予めデータベース部１７００に記憶されている閾値以上であるか否かが電池劣化診断部１４２０で判定される。このとき、ステップ１０２で得られた当該単電池１２１０の電流から電流レートが求められ、この電流レートに基づいて、データベース部１７００に記憶されている電流レート毎の様々な閾値の中から、どの閾値を判定に用いるかが決定される。肯定判定されればステップ１０６に進み、否定判定されればステップ１０２に戻る。 <Step 105>
Whether or not the cumulative number of AE events calculated in step 104 is equal to or greater than a threshold value stored in advance in database unit 1700 is determined by battery deterioration diagnosis unit 1420. At this time, a current rate is obtained from the current of the unit cell 1210 obtained in step 102, and based on this current rate, which threshold value is selected from various threshold values for each current rate stored in the database unit 1700. Is used for determination. If a positive determination is made, the process proceeds to step 106, and if a negative determination is made, the process returns to step 102.
＜ステップ１０６＞
　リチウムイオン二次電池から検出されたＡＥ事象累積数が閾値以上となったことを示す信号、すなわち電池特性劣化を示す信号を、電池劣化診断部１４２０が、セルコントローラ１２２０や、モジュールコントローラ１４００に出力する。 <Step 106>
The battery deterioration diagnosis unit 1420 outputs a signal indicating that the cumulative number of AE events detected from the lithium ion secondary battery is equal to or greater than the threshold, that is, a signal indicating battery characteristic deterioration, to the cell controller 1220 or the module controller 1400. To do.
　以上のように、本実施形態によれば、以下のような作用効果を奏することができる。
（１）本実施形態のリチウムイオン二次電池システムは、電池モジュール１２００の充電時または放電時に、単電池群１２３０あるいは単電池１２１０の内部で発生したアコースティックエミッション信号（ＡＥ信号）を検出するＡＥセンサ１２２６と、ＡＥ信号に基づいてＡＥパラメータであるＡＥ事象数を取得するＡＥ信号検出部１２２５と、ＡＥ事象数に基づいてＡＥ累積パラメータであるＡＥ事象累積数を取得するＡＥコントローラ１４１０と、ＡＥ事象累積数に基づいて、電池モジュール１２００の劣化を診断する電池劣化診断部１４２０と、を備える。
　これによって、リチウムイオン二次電池の劣化を簡便に診断することができる。 As described above, according to the present embodiment, the following operational effects can be achieved.
(1) The lithium ion secondary battery system of the present embodiment includes an AE sensor that detects an acoustic emission signal (AE signal) generated inside the cell group 1230 or the cell 1210 when the battery module 1200 is charged or discharged. 1226, an AE signal detector 1225 that acquires the number of AE events that are AE parameters based on the AE signal, an AE controller 1410 that acquires the number of AE events that are AE cumulative parameters based on the number of AE events, and an AE event A battery deterioration diagnosis unit 1420 for diagnosing deterioration of the battery module 1200 based on the cumulative number.
Thereby, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
（２）第１実施形態の二次電池システムの電池劣化診断部１４２０は、ＡＥ累積パラメータであるＡＥ事象累積数と劣化判定用の閾値とを比較して、リチウムイオン二次電池の劣化を診断する。たとえば、実験で予め算出した劣化判定用閾値がデータベース部１７００に記憶されており、ＡＥ事象累積数が劣化判定用閾値を超えたときに二次電池が劣化したと判定することができる。したがって、電池モジュール１２００の劣化を簡便に診断することができる。 (2) The battery deterioration diagnosis unit 1420 of the secondary battery system according to the first embodiment diagnoses the deterioration of the lithium ion secondary battery by comparing the AE event cumulative number that is the AE cumulative parameter and the threshold for deterioration determination. To do. For example, a threshold value for deterioration determination calculated in advance in an experiment is stored in the database unit 1700, and it can be determined that the secondary battery has deteriorated when the cumulative number of AE events exceeds the threshold value for deterioration determination. Therefore, it is possible to easily diagnose the deterioration of the battery module 1200.
（３）第１実施形態の二次電池システムは、電池モジュール１２００の充放電電流を検出する電流検出部１１００をさらに備える。また、劣化判定用閾値は電流レートに対応して算出されて記憶されている。所定の電流レートで二次電池システムが充放電を繰り返す場合は検出された電流に対応する閾値を読み出し、ＡＥ事象累積数が読み出した閾値を超えたときに電池が劣化したと判定する。したがって、二次電池の充放電電流のレートに対応する閾値を使用して精度よく二次電池の劣化を判定することができる。 (3) The secondary battery system of the first embodiment further includes a current detection unit 1100 that detects the charge / discharge current of the battery module 1200. Further, the deterioration determination threshold value is calculated and stored corresponding to the current rate. When the secondary battery system repeats charging and discharging at a predetermined current rate, a threshold value corresponding to the detected current is read, and it is determined that the battery has deteriorated when the cumulative number of AE events exceeds the read threshold value. Therefore, the deterioration of the secondary battery can be accurately determined using the threshold value corresponding to the charge / discharge current rate of the secondary battery.
　車載用途の二次電池システムのように充放電電流が変動する場合には、変動する充放電電流を模擬した混合電流レートで実験を予め行って、内部抵抗が所定値を超えるＡＥ事象累積数を求めておき、その事象数を劣化判定用閾値としてデータベース部１７００に記憶しておくこともできる。この場合、複数の混合電流レートに対応する閾値を予め算出してデータベース部１７００に記憶しておき、電流検出部１１００により検出した電流の変動の程度に応じた最適な混合電流レートを判定し、この混合電流レートに対応する劣化判定用閾値をデータベース部１７００から読み出せば、充放電電流が変動する二次電池システムでもＡＥ事象累積数に基づいて電流レートに応じた電池劣化判定を精度良く行うことができる。 When the charge / discharge current fluctuates as in a secondary battery system for in-vehicle use, an experiment is performed in advance at a mixed current rate that simulates the fluctuating charge / discharge current, and the cumulative number of AE events whose internal resistance exceeds a predetermined value The number of events can be obtained and stored in the database unit 1700 as a deterioration determination threshold value. In this case, threshold values corresponding to a plurality of mixed current rates are calculated in advance and stored in the database unit 1700, and an optimal mixed current rate is determined according to the degree of current fluctuation detected by the current detection unit 1100. If the deterioration determination threshold value corresponding to the mixed current rate is read from the database unit 1700, the battery deterioration determination according to the current rate is accurately performed based on the cumulative number of AE events even in the secondary battery system in which the charge / discharge current varies. be able to.
―第２実施形態―
　図７に示す本実施形態に係るリチウムイオン二次電池の劣化診断のフロー図を用いて、本実施形態に係るリチウムイオン二次電池の劣化診断を説明する。第２実施形態は、ＡＥ事象累積数と電流から内部抵抗を算出し、この内部抵抗が所定値以上の時に劣化と診断するものである。したがって、図５に示す対応関係を予め作成してデータベース部１７００に記憶されている。なお、本実施形態を説明するにあたり、第１実施形態と同様の箇所については説明を省略する。 -Second embodiment-
The deterioration diagnosis of the lithium ion secondary battery according to the present embodiment will be described using the flowchart of the deterioration diagnosis of the lithium ion secondary battery according to the present embodiment shown in FIG. In the second embodiment, the internal resistance is calculated from the cumulative number of AE events and the current, and the deterioration is diagnosed when the internal resistance is a predetermined value or more. Therefore, the correspondence shown in FIG. 5 is created in advance and stored in the database unit 1700. In the description of the present embodiment, the description of the same parts as in the first embodiment will be omitted.
＜ステップ２０１＞
　リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 201>
A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ２０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００からの信号を受信すると、電圧検出回路１２２１は、各単電池１２１０の端子間電圧を測定する。制御回路１２２３は、電圧検出回路１２２１の測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００に送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００に送信する。モジュールコントローラ１４００は、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 202>
When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
＜ステップ２０３＞
　ステップ２０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象数が測定される。 <Step 203>
Based on the current and battery voltage of each single battery 1210 obtained in step 202, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
＜ステップ２０４＞
　モジュールコントローラ１４００のＡＥコントローラ１４１０において、ステップ２０３でＡＥ信号検出部１２２５により測定されたＡＥ事象数をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積数を演算する。 <Step 204>
In the AE controller 1410 of the module controller 1400, the number of AE events measured by the AE signal detection unit 1225 in step 203 is acquired from the cell controller 1220, and this is integrated over time to calculate the cumulative number of AE events.
＜ステップ２０５＞
　電池劣化診断部１４２０では、ステップ２０４で演算されたＡＥ事象累積数と、電流レートと、データベース部１７００に予め記憶されている電流レートに対応したＡＥ事象累積数と電池内部抵抗変化の対応関係（図５参照）とから電池内部抵抗を取得する。 <Step 205>
In the battery deterioration diagnosis unit 1420, a correspondence relationship between the cumulative number of AE events calculated in step 204, the current rate, the cumulative number of AE events corresponding to the current rate stored in the database unit 1700 in advance, and the battery internal resistance change ( The battery internal resistance is obtained from (see FIG. 5).
＜ステップ２０６＞
　上述の電池内部抵抗が所定値以上になっている場合は、電池劣化診断部１４２０は、電池が劣化したと診断する。電池内部抵抗の演算結果は、電池劣化診断部１４２０からセルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００の情報を基に、充放電状態を管理し、制御する。 <Step 206>
When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400.
　以上のように、本実施形態によれば、以下のような作用効果を奏する。
　本実施形態のリチウムイオン二次電池システムは、電池モジュール１２００（単電池群１２３０、単電池１２１０）の電流を検出する電流検出部１１００をさらに備え、電池劣化診断部１４２０は、ＡＥ累積パラメータであるＡＥ事象累積数と電流レートと電池内部抵抗との対応関係（図５）を用いて、ＡＥ事象累積数と検出した電流値とにより図５の対応関係を参照して、電池内部抵抗を算出し、電池内部抵抗が所定値以上のときは、リチウムイオン二次電池が劣化していると診断する。
　これによって、第１実施形態と同様に、リチウムイオン二次電池の劣化を簡便に診断することができる。 As mentioned above, according to this embodiment, there exist the following effects.
The lithium ion secondary battery system of this embodiment further includes a current detection unit 1100 that detects the current of the battery module 1200 (single cell group 1230, single cell 1210), and the battery deterioration diagnosis unit 1420 is an AE cumulative parameter. Using the correspondence between the cumulative number of AE events, current rate, and battery internal resistance (FIG. 5), the internal resistance of the battery is calculated by referring to the correspondence of FIG. 5 based on the cumulative number of AE events and the detected current value. When the battery internal resistance is equal to or higher than a predetermined value, it is diagnosed that the lithium ion secondary battery is deteriorated.
Accordingly, as in the first embodiment, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
―第３実施形態―
　図８に示す対応関係と、図９に示す本実施形態に係るリチウムイオン二次電池の劣化診断のフロー図とを用いて、本実施形態に係るリチウムイオン二次電池の劣化診断を説明する。なお、本実施形態は、ＡＥパラメータがＡＥ事象強度で、ＡＥ累積パラメータがＡＥ事象累積強度となっている点以外は、第１実施形態と同様であり、本実施形態を説明するにあたり、第１実施形態と同様の箇所については説明を省略する。 -Third embodiment-
The deterioration diagnosis of the lithium ion secondary battery according to this embodiment will be described using the correspondence relationship shown in FIG. 8 and the flowchart of the deterioration diagnosis of the lithium ion secondary battery according to this embodiment shown in FIG. Note that this embodiment is the same as the first embodiment except that the AE parameter is the AE event intensity and the AE cumulative parameter is the AE event cumulative intensity. A description of the same parts as in the embodiment will be omitted.
　図８は、ＡＥ事象累積強度と電池内部抵抗変化の対応関係を示す図である。横軸はＡＥ事象累積強度、縦軸は電池内部抵抗の変化を示している。４本示されている曲線のうちの３本は、電流レート１～３でそれぞれ充放電したときの曲線を示している。なお、電流レート１～３において、
　電流レート１　＜　電流レート２　＜　電流レート３
という大小関係がある。 FIG. 8 is a diagram showing a correspondence relationship between the AE event cumulative intensity and the battery internal resistance change. The horizontal axis represents the AE event cumulative intensity, and the vertical axis represents the change in battery internal resistance. Of the four curves shown, three show curves when charging and discharging at current rates 1 to 3, respectively. At current rates 1 to 3,
Current rate 1 <current rate 2 <current rate 3
There is a big and small relationship.
　残りの１本は、電流レート１～３なども含む様々な電流レートが混合した一般的な使用状態を示す混合電流レートで充放電を行ったときの曲線を示している。一般的な使用状態とは、例えば、本発明による二次電池システムが車載用として用いられたとき、平均的なユーザが運転した場合に得られる曲線を示している。なお、様々な使用状態に対する内部抵抗変化を調べてデータベース化することで混合電流レートの曲線を増やすことができる。 The remaining one shows a curve when charging / discharging is performed at a mixed current rate indicating a general use state in which various current rates including current rates 1 to 3 are mixed. The general usage state indicates, for example, a curve obtained when an average user operates when the secondary battery system according to the present invention is used for in-vehicle use. It is possible to increase the curve of the mixed current rate by examining the internal resistance change with respect to various usage states and creating a database.
　それぞれの電流レートにおいて、ＡＥ事象累積強度が大きくなると電池内部抵抗変化も大きくなる。したがって、初期の内部抵抗に内部抵抗変化分を加算すると経年変化後の内部抵抗が算出できる。
　内部抵抗が所定値以上となったときに二次電池が劣化したと定義し、ＡＥ事象累積強度と内部抵抗変化との対応関係を予め実験やシミュレーションにより求めて、所定値以上の内部抵抗となるＡＥ事象累積強度を閾値として記憶する。本実施形態では、様々な電流レートに対応した閾値が予め算出されてデータベース部１７００に記憶されている。 At each current rate, the battery internal resistance change increases as the AE event cumulative intensity increases. Therefore, by adding the internal resistance change to the initial internal resistance, the internal resistance after aging can be calculated.
It is defined that the secondary battery has deteriorated when the internal resistance exceeds a predetermined value, and the correlation between the AE event cumulative intensity and the internal resistance change is obtained in advance by experiments and simulations, and the internal resistance becomes a predetermined value or more. The AE event cumulative intensity is stored as a threshold value. In the present embodiment, threshold values corresponding to various current rates are calculated in advance and stored in the database unit 1700.
　以下、図９に示すフロー図を用いて、本実施形態の劣化診断について説明する。 Hereinafter, the deterioration diagnosis of this embodiment will be described with reference to the flowchart shown in FIG.
＜ステップ３０１＞
　リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 301>
A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ３０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００からの信号を受信すると、電圧検出回路１２２１は、各単電池１２１０の端子間電圧を測定する。制御回路１２２３は、電圧検出回路１２２１の測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００に送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００に送信する。モジュールコントローラ１４００は、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 302>
When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
＜ステップ３０３＞
　ステップ３０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象強度が測定される。 <Step 303>
Based on the current and battery voltage of each single battery 1210 obtained in step 302, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
＜ステップ３０４＞
　モジュールコントローラ１４００のＡＥコントローラ１４１０において、ステップ３０３でＡＥ信号検出部１２２５により測定されたＡＥ事象強度をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積強度を演算する。 <Step 304>
In the AE controller 1410 of the module controller 1400, the AE event intensity measured by the AE signal detection unit 1225 in step 303 is acquired from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
＜ステップ３０５＞
　ステップ３０４で演算されたＡＥ事象累積強度が、予めデータベース部１７００に記憶されている閾値以上であるか否かが電池劣化診断部１４２０で判定される。このとき、ステップ３０２で得られた当該単電池１２１０の電流から電流レートが求められ、この電流レートに基づいて、データベース部１７００に記憶されている電流レート毎の様々な閾値の中から、どの閾値を判定に用いるかが決定される。肯定判定されればステップ３０６に進み、否定判定されればステップ３０２に戻る。 <Step 305>
The battery deterioration diagnosis unit 1420 determines whether or not the AE event cumulative intensity calculated in step 304 is equal to or greater than a threshold value stored in the database unit 1700 in advance. At this time, a current rate is obtained from the current of the unit cell 1210 obtained in step 302, and based on this current rate, which threshold value is selected from various threshold values for each current rate stored in the database unit 1700. Is used for determination. If a positive determination is made, the process proceeds to step 306, and if a negative determination is made, the process returns to step 302.
＜ステップ３０６＞
　リチウムイオン二次電池から検出されたＡＥ事象累積強度が閾値以上となったことを示す信号を、電池劣化診断部１４２０が、セルコントローラ１２２０や、モジュールコントローラ１４００に出力する。 <Step 306>
The battery deterioration diagnosis unit 1420 outputs a signal indicating that the AE event cumulative intensity detected from the lithium ion secondary battery is equal to or greater than the threshold value to the cell controller 1220 or the module controller 1400.
　以上より、本実施形態においても、第１実施形態と同様に、リチウムイオン二次電池の劣化を簡便に診断することができる。 From the above, also in this embodiment, as in the first embodiment, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
―第４実施形態―
　図１０に示す本実施形態に係るリチウムイオン二次電池の劣化診断のフロー図を用いて、本実施形態に係るリチウムイオン二次電池の劣化診断を説明する。なお、本実施形態を説明するにあたり、第１実施形態と同様の箇所については説明を省略する。また、本実施形態は、ＡＥパラメータがＡＥ事象強度で、ＡＥ累積パラメータがＡＥ事象累積強度となっている点以外は、第２実施形態と同様である。 -Fourth embodiment-
The deterioration diagnosis of the lithium ion secondary battery according to the present embodiment will be described using the flowchart of the deterioration diagnosis of the lithium ion secondary battery according to the present embodiment shown in FIG. In the description of the present embodiment, the description of the same parts as in the first embodiment will be omitted. This embodiment is the same as the second embodiment except that the AE parameter is the AE event intensity and the AE cumulative parameter is the AE event cumulative intensity.
＜ステップ４０１＞
　リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 401>
A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ４０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００からの信号を受信すると、電圧検出回路１２２１は、各単電池１２１０の端子間電圧を測定する。制御回路１２２３は、電圧検出回路１２２１の測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００に送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００に送信する。モジュールコントローラ１４００は、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 402>
When the cell controller 1220 receives a signal from the module controller 1400, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The control circuit 1223 receives the measurement result of the voltage detection circuit 1221 and transmits it to the module controller 1400 via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
＜ステップ４０３＞
　ステップ４０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象強度が測定される。 <Step 403>
Based on the current and battery voltage of each single battery 1210 obtained in step 402, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
＜ステップ４０４＞
　モジュールコントローラ１４００のＡＥコントローラ１４１０において、ステップ４０３でＡＥ信号検出部１２２５により測定されたＡＥ事象強度をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積強度を演算する。 <Step 404>
In the AE controller 1410 of the module controller 1400, the AE event intensity measured by the AE signal detection unit 1225 in step 403 is acquired from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
＜ステップ４０５＞
　電池劣化診断部１４２０では、ステップ４０４で演算されたＡＥ事象累積強度と、電流レートと、データベース部１７００に予め記憶されている電流レートに対応したＡＥ事象累積強度と電池内部抵抗変化の対応関係（図８参照）とから電池内部抵抗を取得する。 <Step 405>
In battery deterioration diagnosis unit 1420, the correspondence relationship between the AE event cumulative intensity calculated in step 404, the current rate, the AE event cumulative intensity corresponding to the current rate stored in advance in database unit 1700, and the battery internal resistance change ( The internal resistance of the battery is obtained from (see FIG. 8).
＜ステップ４０６＞
　上述の電池内部抵抗が所定値以上になっている場合は、電池劣化診断部１４２０は、電池が劣化したと診断する。電池内部抵抗の演算結果は、電池劣化診断部１４２０からセルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００の情報を基に、充放電状態を管理し、制御する。 <Step 406>
When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400.
　以上より、本実施形態においても、第１実施形態と同様に、リチウムイオン二次電池の劣化を簡便に診断することができる。 From the above, also in this embodiment, as in the first embodiment, it is possible to easily diagnose the deterioration of the lithium ion secondary battery.
―第５実施形態―
　本実施形態を説明するにあたり、第１実施形態と同様の箇所は説明を省略する。本実施形態におけるリチウムイオン二次電池システムは、図４に示すモジュールコントローラ１４００に代えて、図１１に示すモジュールコントローラ１４００Ａを備えている。 -Fifth embodiment-
In the description of the present embodiment, the description of the same parts as in the first embodiment will be omitted. The lithium ion secondary battery system in this embodiment includes a module controller 1400A shown in FIG. 11 instead of the module controller 1400 shown in FIG.
　モジュールコントローラ１４００Ａは、ＡＥコントローラ１４１０と電池劣化診断部１４２０と電流制限値演算部１４３０で構成される。ＡＥコントローラ１４１０と電池劣化診断部１４２０と電流制限値演算部１４３０は、たとえばマイクロコンピュータであるモジュールコントローラ１４００Ａにおいて所定のソフトウェアを実行することにより、それぞれ実現される。 The module controller 1400A includes an AE controller 1410, a battery deterioration diagnosis unit 1420, and a current limit value calculation unit 1430. The AE controller 1410, the battery deterioration diagnosis unit 1420, and the current limit value calculation unit 1430 are realized by executing predetermined software in the module controller 1400A, which is a microcomputer, for example.
　図１２に示す本実施形態に係る電池劣化診断のフロー図を用いて、本実施形態に係る電池劣化診断について説明する。 The battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart of the battery deterioration diagnosis according to this embodiment shown in FIG.
＜ステップ５０１＞
　リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 501>
A signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ５０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００Ａからの信号を受信すると、電圧検出回路１２２１は、各単電池１２１０の端子間電圧を測定する。温度検出部１２２２は、単電池群１２３０の温度を測定する。制御回路１２２３は、電圧検出回路１２２１および温度検出部１２２２からの測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００Ａに送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００Ａに送信する。モジュールコントローラ１４００Ａは、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 502>
When the cell controller 1220 receives a signal from the module controller 1400A, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The temperature detection unit 1222 measures the temperature of the cell group 1230. The control circuit 1223 receives measurement results from the voltage detection circuit 1221 and the temperature detection unit 1222 and transmits the measurement results to the module controller 1400A via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400A. The module controller 1400A converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
　＜ステップ５０３＞
　ステップ５０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象数が測定される。 <Step 503>
Based on the current and battery voltage of each single battery 1210 obtained in step 502, battery deterioration diagnosis unit 1420 determines whether or not each single battery 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. From this, the number of AE events is measured.
＜ステップ５０４＞
　モジュールコントローラ１４００ＡのＡＥコントローラ１４１０において、ステップ５０３でＡＥ信号検出部１２２５により測定されたＡＥ事象数をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積数を演算する。 <Step 504>
In the AE controller 1410 of the module controller 1400A, the number of AE events measured by the AE signal detection unit 1225 in step 503 is acquired from the cell controller 1220, and this is integrated with time to calculate the cumulative number of AE events.
＜ステップ５０５＞
　電池劣化診断部１４２０では、ステップ５０４で演算されたＡＥ事象累積数と、電流レートと、データベース部１７００に予め記憶されていた電流レートに対応したＡＥ事象累積数と電池内部抵抗変化の対応関係（図５参照）とから電池内部抵抗を取得する。 <Step 505>
In the battery deterioration diagnosis unit 1420, the correspondence relationship between the cumulative number of AE events calculated in step 504, the current rate, the cumulative number of AE events corresponding to the current rate stored in advance in the database unit 1700, and the battery internal resistance change ( The battery internal resistance is obtained from (see FIG. 5).
＜ステップ５０６＞
　上述の電池内部抵抗が所定値以上になっている場合は、電池劣化診断部１４２０は、電池が劣化したと診断する。電池内部抵抗の演算結果は、電池劣化診断部１４２０からセルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００Ａの情報を基に、充放電状態を管理し、制御する。 <Step 506>
When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400A.
＜ステップ５０７＞
　電池が劣化したと診断した場合、電流制限値演算部１４３０にて、ＡＥ事象累積数と電池内部抵抗変化の関係から求められた電池内部抵抗から電池電圧、温度を用いて以下のようにして制限電流値を演算する。
　制限充電電流値をＩｃｍａｘ、制限放電電流値をＩｄｍａｘとすると、Ｉｃｍａｘ、Ｉｄｍａｘはそれぞれ下記の（式１）、（式２）で演算される。（式１）、（式２）において、Ｒ１はＡＥ事象累積数から求められた電池内部抵抗、Ｖｍａｘは単電池１２１０の上限電圧、Ｖｍｉｎは単電池１２１０の下限電圧、ＯＣＶは単電池１２１０の開回路電圧である。ＯＣＶは、ステップ５０２で得られた電池電圧から内部抵抗による電圧変化分を差し引いて求められる。
Ｉｃｍａｘ＝（Ｖｍａｘ－ＯＣＶ）／Ｒ１（式１）
Ｉｄｍａｘ＝（ＯＣＶ－Ｖｍｉｎ）／Ｒ１（式２）
　（式１）、（式２）の電池内部抵抗Ｒ１は、ステップ５０５において、電池電圧、電流、温度、時間から算出される。充放電サイクルに対する内部抵抗の増加率は、環境温度によって傾向が大きく異なる。そのため、温度変化に応じて内部抵抗の閾値である制限値は適宜設定することが望ましい。 <Step 507>
When diagnosing that the battery has deteriorated, the current limit value calculation unit 1430 uses the battery voltage and temperature from the battery internal resistance obtained from the relationship between the cumulative number of AE events and the change in battery internal resistance to limit as follows. Calculate the current value.
Assuming that the limited charging current value is Icmax and the limited discharging current value is Idmax, Icmax and Idmax are calculated by the following (Formula 1) and (Formula 2), respectively. In (Equation 1) and (Equation 2), R1 is the battery internal resistance obtained from the cumulative number of AE events, Vmax is the upper limit voltage of the unit cell 1210, Vmin is the lower limit voltage of the unit cell 1210, and OCV is the open state of the unit cell 1210. Circuit voltage. The OCV is obtained by subtracting the voltage change due to the internal resistance from the battery voltage obtained in step 502.
Icmax = (Vmax−OCV) / R1 (Formula 1)
Idmax = (OCV−Vmin) / R1 (Formula 2)
In step 505, the battery internal resistance R1 in (Expression 1) and (Expression 2) is calculated from the battery voltage, current, temperature, and time. The tendency of the increase rate of the internal resistance with respect to the charge / discharge cycle varies greatly depending on the environmental temperature. Therefore, it is desirable to appropriately set a limit value that is a threshold value of the internal resistance in accordance with a temperature change.
＜ステップ５０８＞
　モジュールコントローラ１４００Ａの電流制限値演算部１４３０により算出された充放電電流制限値の計算結果は、セルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００Ａの情報を基に、各単電池１２１０の充放電電流値を、ステップ５０６で電池が劣化したと判断される前の値より小さくする。 <Step 508>
The calculation result of the charge / discharge current limit value calculated by the current limit value calculation unit 1430 of the module controller 1400A is transmitted to the cell controller 1220 and the system controller 1500. Based on information from module controller 1400A, system controller 1500 sets the charging / discharging current value of each unit cell 1210 to be smaller than the value before it is determined in step 506 that the battery has deteriorated.
　以上のように、本実施形態によれば、第１実施形態と同様の作用効果に加え、以下のような作用効果を奏する。
　本実施形態のリチウムイオン二次電池システムは、電池内部抵抗に基づいて、電池モジュール１２００の制限電流値を演算する制限電流値演算部１４３０をさらに備え、その制限電流値に基づいて、電池電流を制限する。
　これによって、急激な電池劣化を抑制することができ、入出力電流を適切に制御することが出来る。 As described above, according to the present embodiment, in addition to the same functions and effects as those of the first embodiment, the following functions and effects are achieved.
The lithium ion secondary battery system of the present embodiment further includes a limit current value calculation unit 1430 that calculates a limit current value of the battery module 1200 based on the battery internal resistance, and the battery current is calculated based on the limit current value. Restrict.
Thereby, rapid battery deterioration can be suppressed, and input / output current can be appropriately controlled.
―第６実施形態―
　本実施形態におけるリチウムイオン二次電池システムは、図４に示すモジュールコントローラ１４００に代えて、図１１に示すモジュールコントローラ１４００Ａを備えている。なお、本実施形態は、ＡＥパラメータがＡＥ事象強度で、ＡＥ累積パラメータがＡＥ事象累積強度となっている点以外は、第５実施形態と同様である。本実施形態を説明するにあたり、第１及び第５実施形態と同様の箇所は説明を省略する。 -Sixth Embodiment-
The lithium ion secondary battery system in this embodiment includes a module controller 1400A shown in FIG. 11 instead of the module controller 1400 shown in FIG. The present embodiment is the same as the fifth embodiment except that the AE parameter is the AE event strength and the AE cumulative parameter is the AE event cumulative strength. In the description of the present embodiment, the description of the same parts as those in the first and fifth embodiments will be omitted.
　図１３に示す本実施形態に係る電池劣化診断のフロー図を用いて、本実施形態に係る電池劣化診断について説明する。 The battery deterioration diagnosis according to this embodiment will be described with reference to the flowchart of battery deterioration diagnosis according to this embodiment shown in FIG.
＜ステップ６０１＞
　最初に、リチウムイオン二次電池の充放電を開始する命令を表す信号をシステムコントローラ１５００から充放電する電池モジュール１２００に送信し、充放電を開始する。 <Step 601>
First, a signal representing an instruction to start charging / discharging of the lithium ion secondary battery is transmitted from the system controller 1500 to the battery module 1200 to be charged / discharged, and charging / discharging is started.
＜ステップ６０２＞
　セルコントローラ１２２０がモジュールコントローラ１４００Ａからの信号を受信すると、電圧検出回路１２２１は各単電池１２１０の端子間電圧を測定する。温度検出部１２２２は、単電池群１２３０の温度を測定する。制御回路１２２３は、電圧検出回路１２２１および温度検出部１２２２からの測定結果を受け取り、信号入出力回路１２２４を介してモジュールコントローラ１４００Ａに送信する。電流検出部１１００は電池モジュール１２００の電流を測定し、モジュールコントローラ１４００に送信する。モジュールコントローラ１４００は、電池モジュール１２００内の各単電池１２１０の構成に合わせた変換方法を用いて、電池モジュール１２００の電流を各単電池１２１０の電流に変換する。 <Step 602>
When the cell controller 1220 receives a signal from the module controller 1400A, the voltage detection circuit 1221 measures the voltage between the terminals of each unit cell 1210. The temperature detection unit 1222 measures the temperature of the cell group 1230. The control circuit 1223 receives measurement results from the voltage detection circuit 1221 and the temperature detection unit 1222 and transmits the measurement results to the module controller 1400A via the signal input / output circuit 1224. The current detection unit 1100 measures the current of the battery module 1200 and transmits it to the module controller 1400. The module controller 1400 converts the current of the battery module 1200 into the current of each unit cell 1210 using a conversion method that matches the configuration of each unit cell 1210 in the battery module 1200.
＜ステップ６０３＞
　ステップ６０２で得られた各単電池１２１０の電流と電池電圧に基づき、電池劣化診断部１４２０において各単電池１２１０が充放電状態にあるか否かが判別される。その結果、少なくとも一つの単電池１２１０が充放電状態にあると判別されると、電池劣化診断部１４２０の指令に基づいて、ＡＥセンサ１２２６によりＡＥ信号が検出され、ＡＥ信号検出部１２２５によりＡＥ信号からＡＥ事象強度が測定される。 <Step 603>
Based on the current and battery voltage of each cell 1210 obtained in step 602, battery deterioration diagnosis unit 1420 determines whether or not each cell 1210 is in a charge / discharge state. As a result, when it is determined that at least one unit cell 1210 is in a charge / discharge state, an AE signal is detected by the AE sensor 1226 based on a command from the battery deterioration diagnosis unit 1420, and an AE signal is detected by the AE signal detection unit 1225. AE event intensity is measured.
＜ステップ６０４＞
　モジュールコントローラ１４００ＡのＡＥコントローラ１４１０において、ステップ６０３でＡＥ信号検出部１２２５により測定されたＡＥ事象強度をセルコントローラ１２２０から取得し、これを時間積算してＡＥ事象累積強度を演算する。 <Step 604>
In the AE controller 1410 of the module controller 1400A, the AE event intensity measured by the AE signal detection unit 1225 in step 603 is obtained from the cell controller 1220, and this is integrated over time to calculate the AE event accumulated intensity.
＜ステップ６０５＞
　電池劣化診断部１４２０では、ステップ６０４で演算されたＡＥ事象累積強度と、電流レートと、データベース部１７００に予め記憶されていた電流レートに対応したＡＥ事象累積強度と電池内部抵抗変化の対応関係（図８参照）とから電池内部抵抗を取得する。 <Step 605>
In the battery deterioration diagnosis unit 1420, a correspondence relationship between the AE event cumulative intensity calculated in step 604, the current rate, the AE event cumulative intensity corresponding to the current rate stored in the database unit 1700 in advance, and the battery internal resistance change ( The internal resistance of the battery is obtained from (see FIG. 8).
＜ステップ６０６＞
　上述の電池内部抵抗が所定値以上になっている場合は、電池劣化診断部１４２０は、電池が劣化したと診断する。電池内部抵抗の演算結果は、電池劣化診断部１４２０からセルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００Ａの情報を基に、充放電状態を管理し、制御する。 <Step 606>
When the above-described battery internal resistance is equal to or greater than a predetermined value, the battery deterioration diagnosis unit 1420 diagnoses that the battery has deteriorated. The calculation result of the battery internal resistance is transmitted from the battery deterioration diagnosis unit 1420 to the cell controller 1220 and the system controller 1500. The system controller 1500 manages and controls the charge / discharge state based on the information of the module controller 1400A.
＜ステップ６０７＞
　電池が劣化したと判断した場合、電流制限値演算部１４３０にて、ＡＥ事象累積強度と電池内部抵抗変化の関係から求められた電池内部抵抗から電池電圧、温度を用いて以下のようにして制限電流値を演算する。
　制限充電電流値をＩｃｍａｘ、制限放電電流値をＩｄｍａｘとすると、Ｉｃｍａｘ、Ｉｄｍａｘはそれぞれ下記の（式３）、（式４）で演算される。（式３）、（式４）において、Ｒ２はＡＥ事象累積強度から求められた電池内部抵抗、Ｖｍａｘは単電池１２１０の上限電圧、Ｖｍｉｎは単電池１２１０の下限電圧、ＯＣＶは単電池１２１０の開回路電圧である。ＯＣＶは、ステップ６０２で得られた電池電圧から内部抵抗による電圧変化分を差し引いて求められる。
Ｉｃｍａｘ＝（Ｖｍａｘ－ＯＣＶ）／Ｒ２（式３）
Ｉｄｍａｘ＝（ＯＣＶ－Ｖｍｉｎ）／Ｒ２（式４）
　（式３）、（式４）の電池内部抵抗Ｒ２は、ステップ６０５において、電池電圧、電流、温度、時間から算出される。充放電サイクルに対する内部抵抗の増加率は、環境温度によって傾向が大きく異なる。そのため、温度変化に応じて内部抵抗の閾値である制限値は適宜設定することが望ましい。 <Step 607>
When it is determined that the battery has deteriorated, the current limit value calculation unit 1430 limits the battery voltage and temperature from the battery internal resistance obtained from the relationship between the AE event cumulative intensity and the battery internal resistance change as follows. Calculate the current value.
Assuming that the limited charging current value is Icmax and the limited discharging current value is Idmax, Icmax and Idmax are calculated by the following (Equation 3) and (Equation 4), respectively. In (Equation 3) and (Equation 4), R2 is the battery internal resistance obtained from the AE event cumulative intensity, Vmax is the upper limit voltage of the unit cell 1210, Vmin is the lower limit voltage of the unit cell 1210, and OCV is the open state of the unit cell 1210. Circuit voltage. The OCV is obtained by subtracting the voltage change due to the internal resistance from the battery voltage obtained in step 602.
Icmax = (Vmax−OCV) / R2 (Formula 3)
Idmax = (OCV−Vmin) / R2 (Formula 4)
In step 605, the battery internal resistance R2 in (Expression 3) and (Expression 4) is calculated from the battery voltage, current, temperature, and time. The tendency of the increase rate of the internal resistance with respect to the charge / discharge cycle varies greatly depending on the environmental temperature. Therefore, it is desirable to appropriately set a limit value that is a threshold value of the internal resistance in accordance with a temperature change.
＜ステップ６０８＞
　モジュールコントローラ１４００Ａの電流制限値演算部１４３０により算出された充放電電流制限値の計算結果は、セルコントローラ１２２０やシステムコントローラ１５００に送信される。システムコントローラ１５００は、モジュールコントローラ１４００Ａの情報を基に、各単電池１２１０の充放電電流値を、ステップ６０６で電池が劣化したと判断される前の充放電電流値より小さくする。 <Step 608>
The calculation result of the charge / discharge current limit value calculated by the current limit value calculation unit 1430 of the module controller 1400A is transmitted to the cell controller 1220 and the system controller 1500. Based on the information of module controller 1400A, system controller 1500 makes the charging / discharging current value of each single battery 1210 smaller than the charging / discharging current value before it is determined in step 606 that the battery has deteriorated.
　以上のように、本実施形態によれば、第５実施形態と同様に、急激な電池劣化を抑制することができ、入出力電流を適切に制御することが出来る。 As described above, according to the present embodiment, as in the fifth embodiment, rapid battery deterioration can be suppressed, and the input / output current can be appropriately controlled.
　以上に示した第１～第６実施形態によれば、コンピュータであるモジュールコントローラ１４００を用いて、以下の手順（Ａ）～（Ｃ）でリチウムイオン二次電池の劣化診断をすることができる。
（Ａ）モジュールコントローラ１４００のＡＥコントローラ１４１０により、電池モジュール１２００の充電時または放電時に、単電池群１２３０、または、単電池１２１０の内部で発生してＡＥセンサ１２２６により検出されたアコースティックエミッション信号（ＡＥ信号）に基づいたＡＥパラメータであるＡＥ事象数、ＡＥ事象強度を、ＡＥ信号検出部１２２５から取得する。（ステップ１０４、２０４、３０４、４０４、５０４、６０４）
（Ｂ）モジュールコントローラ１４００のＡＥコントローラ１４１０により、取得したＡＥパラメータに基づいてＡＥ累積パラメータであるＡＥ事象累積数、ＡＥ事象累積強度を取得する。（ステップ１０４、２０４、３０４、４０４、５０４、６０４）
（Ｃ）モジュールコントローラ１４００の電池劣化診断部１４２０により、ＡＥ累積パラメータに基づいて、電池モジュール１２００の劣化を診断する。内部抵抗は温度によって変化するので、温度検出部１２２２で測定された温度を考慮した上で、上述の劣化診断を行う。（ステップ１０５、２０６、３０５、４０６、５０６、６０６） According to the first to sixth embodiments described above, the deterioration diagnosis of the lithium ion secondary battery can be performed by the following procedures (A) to (C) using the module controller 1400 which is a computer.
(A) When the battery module 1200 is charged or discharged by the AE controller 1410 of the module controller 1400, an acoustic emission signal (AE) generated inside the single cell group 1230 or the single cell 1210 and detected by the AE sensor 1226 The AE event number and the AE event intensity, which are AE parameters based on the signal), are acquired from the AE signal detection unit 1225. (Steps 104, 204, 304, 404, 504, 604)
(B) The AE controller 1410 of the module controller 1400 acquires the AE event cumulative number and the AE event cumulative strength, which are AE cumulative parameters, based on the acquired AE parameters. (Steps 104, 204, 304, 404, 504, 604)
(C) The battery deterioration diagnosis unit 1420 of the module controller 1400 diagnoses deterioration of the battery module 1200 based on the AE cumulative parameter. Since the internal resistance varies depending on the temperature, the above-described deterioration diagnosis is performed in consideration of the temperature measured by the temperature detection unit 1222. (Steps 105, 206, 305, 406, 506, 606)
　なお、本発明は、以下に示す文献に記載の発明よりも、以下に示す点で優れている。 Note that the present invention is superior to the invention described in the following literature in the following points.
　日本国特開２０１２－２５１９１９号公報には、ＡＥ信号の振幅（ＡＥ発生強度）を充放電電流の一次関数として近似（線形近似）して、その傾きと切片からリチウムイオン二次電池のサイクル数を求めて、リチウムイオン二次電池の劣化を診断する発明が開示されている。当該発明では、サイクル数を推定できるが、電池劣化状態（ＳＯＨ）を診断するに至っていない。 In Japanese Patent Application Laid-Open No. 2012-251919, the amplitude of the AE signal (AE generation intensity) is approximated (linear approximation) as a linear function of the charge / discharge current, and the cycle number of the lithium ion secondary battery is calculated from the slope and intercept. Therefore, an invention for diagnosing deterioration of a lithium ion secondary battery is disclosed. In the invention, the number of cycles can be estimated, but the battery deterioration state (SOH) has not been diagnosed.
　しかし、本発明は、ＡＥ事象数やＡＥ事象強度というＡＥパラメータを累積するだけなので、簡便に電池劣化状態（ＳＯＨ）を診断できる。なお、本発明では、電池劣化状態（ＳＯＨ）を診断するにあたり、ＳＯＨＲ（内部抵抗劣化指数）を診断基準として採用している。 However, since the present invention only accumulates the AE parameters such as the number of AE events and the AE event intensity, the battery deterioration state (SOH) can be easily diagnosed. In the present invention, in diagnosing the battery deterioration state (SOH), SOHR (Internal Resistance Degradation Index) is adopted as a diagnostic criterion.
　日本国特開２０１３－１８７０３１号公報には、１充放電サイクル内において発生するＡＥ事象数が閾値以上である場合に劣化を示す信号を出力する発明が開示されている。当該発明は、１つのＡＥ事象からＡＥ事象数を求めて、それを劣化の判断基準としている。１つのＡＥ事象からＡＥ事象数を求めることは、一時的なノイズなどで誤った測定をした場合に、大きな影響を受ける。また、当該発明は、電池劣化状態（ＳＯＨ）を診断するに至っていない。 Japanese Unexamined Patent Application Publication No. 2013-187031 discloses an invention that outputs a signal indicating deterioration when the number of AE events occurring in one charge / discharge cycle is equal to or greater than a threshold value. In the present invention, the number of AE events is obtained from one AE event, and this is used as a criterion for deterioration. Obtaining the number of AE events from one AE event is greatly affected by erroneous measurement due to temporary noise or the like. Moreover, the said invention has not led to a battery deterioration state (SOH) diagnosis.
　しかし、本発明は、ＡＥ事象数やＡＥ事象強度というＡＥパラメータを累積して得られるＡＥ累積パラメータ（ＡＥ事象累積数またはＡＥ事象累積強度）を用いて電池劣化状態（ＳＯＨ）を診断している。よって、誤った測定値が一部含まれても、大部分は正確な測定値であるため大きな影響を受けることはない。また、ＡＥ累積パラメータ（ＡＥ事象累積数またはＡＥ事象累積強度）を用いることにより電池劣化状態（ＳＯＨ、厳密には、ＳＯＨＲ）を診断することが可能である。 However, in the present invention, the battery deterioration state (SOH) is diagnosed using an AE cumulative parameter (AE event cumulative number or AE event cumulative strength) obtained by accumulating AE parameters such as the number of AE events and the AE event strength. . Therefore, even if some erroneous measurement values are included, most of them are accurate measurement values and thus are not greatly affected. Further, the battery deterioration state (SOH, strictly speaking, SOHR) can be diagnosed by using the AE accumulation parameter (AE event accumulation number or AE event accumulation intensity).
　本発明は、ハイブリッド自動車（ＨＥＶ）、プラグインハイブリッド自動車(ＰＨＥＶ)、電気自動車(ＥＶ)などの乗用車やハイブリッド鉄道車両といった産業用車両の電源を構成する二次電池装置の二次電池制御回路に適用できる。 The present invention relates to a secondary battery control circuit of a secondary battery device that constitutes a power source of an industrial vehicle such as a passenger car such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (EV) or a hybrid railway vehicle. Applicable.
　以上の実施形態は本発明の内容の具体例を示すものであり、本願発明がこれらの実施例に限定されるものではなく、本明細書に開示される技術的思想の範囲内において当業者による様々な変更が可能である。 The embodiments described above show specific examples of the contents of the present invention, and the present invention is not limited to these embodiments, and those skilled in the art within the scope of the technical idea disclosed in this specification. Various changes are possible.
　次の優先権基礎出願の開示内容は引用文としてここに組み込まれる。
　日本国特許出願２０１４年第９２６９４号（２０１４年４月２８日出願） The disclosure of the following priority application is hereby incorporated by reference.
Japanese patent application 2014-92694 (filed April 28, 2014)
１０００：電池装置
１１００：電流検出部
１２００：電池モジュール
１２１０：単電池
１２２０：セルコントローラ
１２２１：電圧検出回路　
１２２２：温度検出部
１２２３：制御回路
１２２４：信号入出力回路 
１２２５：ＡＥ信号検出部
１２２６：ＡＥセンサ
１２３０：単電池群 
１３００：電圧検出部 
１４００、１４００Ａ：モジュールコントローラ
１４１０：ＡＥコントローラ
１４２０：電池劣化診断部
１４３０：電流制限値演算部
１５００：システムコントローラ
１６００：リレー 
１７００：データベース部  
  1000: Battery device 1100: Current detection unit 1200: Battery module 1210: Single battery 1220: Cell controller 1221: Voltage detection circuit
1222: Temperature detector 1223: Control circuit 1224: Signal input / output circuit
1225: AE signal detection unit 1226: AE sensor 1230: single cell group
1300: Voltage detector
1400, 1400A: Module controller 1410: AE controller 1420: Battery deterioration diagnosis unit 1430: Current limit value calculation unit 1500: System controller 1600: Relay
1700: Database section

Claims (8)

  1. 　リチウムイオン二次電池の充電時または放電時に、前記リチウムイオン二次電池の内部で発生したアコースティックエミッション信号を検出するＡＥセンサと、
    　前記アコースティックエミッション信号に基づいてＡＥパラメータを取得するＡＥパラメータ取得部と、
    　前記ＡＥパラメータを累積して、ＡＥ累積パラメータを取得するＡＥ累積パラメータ取得部と、
    　前記ＡＥ累積パラメータに基づいて、前記リチウムイオン二次電池の劣化を診断する電池劣化診断部と、を備えるリチウムイオン二次電池システム。     An AE sensor that detects an acoustic emission signal generated inside the lithium ion secondary battery when the lithium ion secondary battery is charged or discharged;
    An AE parameter acquisition unit that acquires an AE parameter based on the acoustic emission signal;
    An AE cumulative parameter acquisition unit for accumulating the AE parameters and acquiring AE cumulative parameters;
    A lithium ion secondary battery system comprising: a battery deterioration diagnosis unit that diagnoses deterioration of the lithium ion secondary battery based on the AE cumulative parameter.
  2. 　請求項１に記載のリチウムイオン二次電池システムにおいて、
    　前記電池劣化診断部は、前記ＡＥ累積パラメータと所定の閾値とを比較して、前記リチウムイオン二次電池の劣化を診断するリチウムイオン二次電池システム。     In the lithium ion secondary battery system according to claim 1,
    The battery deterioration diagnosis unit is a lithium ion secondary battery system that compares the AE cumulative parameter with a predetermined threshold value to diagnose deterioration of the lithium ion secondary battery.
  3. 　請求項２に記載のリチウムイオン二次電池システムにおいて、
    　前記リチウムイオン二次電池の電流を検出する電流検出部をさらに備え、
    　前記所定の閾値は、予め記憶された前記ＡＥ累積パラメータと前記電流と電池内部抵抗変化との対応関係により決定されるリチウムイオン二次電池システム。     The lithium ion secondary battery system according to claim 2,
    A current detection unit for detecting a current of the lithium ion secondary battery;
    The predetermined threshold value is a lithium ion secondary battery system determined by a correspondence relationship between the AE cumulative parameter stored in advance, the current, and a change in battery internal resistance.
  4. 　請求項１に記載のリチウムイオン二次電池システムにおいて、
    　前記リチウムイオン二次電池の電流を検出する電流検出部をさらに備え、
    　前記電池劣化診断部は、予め記憶された前記ＡＥ累積パラメータと前記電流と電池内部抵抗変化との対応関係に前記ＡＥ累積パラメータを適用して、電池内部抵抗を算出し、前記電池内部抵抗が所定値以上のときは、前記リチウムイオン二次電池が劣化していると診断するリチウムイオン二次電池システム。     In the lithium ion secondary battery system according to claim 1,
    A current detection unit for detecting a current of the lithium ion secondary battery;
    The battery deterioration diagnosis unit calculates the battery internal resistance by applying the AE cumulative parameter to the correspondence relationship between the AE cumulative parameter stored in advance, the current and the battery internal resistance change, and the battery internal resistance is predetermined. A lithium ion secondary battery system that diagnoses that the lithium ion secondary battery has deteriorated when the value is greater than or equal to the value.
  5. 　請求項４に記載のリチウムイオン二次電池システムにおいて、
    　前記算出された電池内部抵抗に基づいて、前記リチウムイオン二次電池の制限電流値を演算する制限電流値演算部をさらに備え、
    　前記制限電流値に基づいて、前記電流を制限するリチウムイオン二次電池システム。     In the lithium ion secondary battery system according to claim 4,
    Based on the calculated battery internal resistance, further comprising a limiting current value calculation unit that calculates a limiting current value of the lithium ion secondary battery,
    A lithium ion secondary battery system that limits the current based on the limit current value.
  6. 　請求項１～５のいずれか一項に記載のリチウムイオン二次電池システムにおいて、
    　前記ＡＥ累積パラメータは、
    　前記ＡＥパラメータがＡＥ事象数である場合には、ＡＥ事象累積数であり、
    　前記ＡＥパラメータがＡＥ事象強度である場合には、ＡＥ事象累積強度であるリチウムイオン二次電池システム。     The lithium ion secondary battery system according to any one of claims 1 to 5,
    The AE cumulative parameter is
    If the AE parameter is the number of AE events, it is the cumulative number of AE events;
    When the AE parameter is an AE event intensity, the lithium ion secondary battery system is an AE event cumulative intensity.
  7. 　請求項１～６のいずれか一項に記載のリチウムイオン二次電池システムにおいて、
    　前記ＡＥセンサは、３０ｋＨｚ以上のＡＥ事象を検出するリチウムイオン二次電池システム。     The lithium ion secondary battery system according to any one of claims 1 to 6,
    The AE sensor is a lithium ion secondary battery system that detects an AE event of 30 kHz or more.
  8. 　コンピュータにより、前記リチウムイオン二次電池の充電時または放電時に前記リチウムイオン二次電池の内部で発生したアコースティックエミッション信号に基づいたＡＥパラメータを取得し、
    　前記コンピュータにより、前記ＡＥパラメータを累積してＡＥ累積パラメータを取得し、
    　前記コンピュータにより、前記ＡＥ累積パラメータに基づいて、前記リチウムイオン二次電池の劣化を診断するリチウムイオン二次電池の劣化診断方法。      The computer acquires an AE parameter based on an acoustic emission signal generated inside the lithium ion secondary battery during charging or discharging of the lithium ion secondary battery,
    The computer accumulates the AE parameters to obtain AE cumulative parameters,
    A deterioration diagnosis method for a lithium ion secondary battery, wherein the computer diagnoses deterioration of the lithium ion secondary battery based on the AE cumulative parameter.
PCT/JP2015/062731 2014-04-28 2015-04-27 Lithium ion secondary battery system, and deterioration diagnosis method for lithium ion secondary battery WO2015166926A1 (en)

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JP2022001007A (en) * 2020-06-19 2022-01-04 矢崎総業株式会社 Battery control unit and battery system

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