Battery management device

Abstract

To provide a battery management device capable of accurately detecting, for example, whether a battery has been replaced using a simple method.SOLUTION: A battery management device that manages a battery mounted on a vehicle comprises: an acquisition unit that acquires data including information related to the battery current and information related to vehicle activation from the vehicle; a derivation unit that derives a cumulative value of the current charged to and discharged from the battery up to the present, and an average value of the current charged / discharged by the battery during the most recent vehicle activation period on the basis of the data; and a determination unit that determines that external charging or replacement of the battery has been performed if the cumulative value of the current is below a first threshold and the average value of the current is below a second threshold.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery management device that manages a battery mounted on a vehicle.

Background Art

[0002] Patent Document 1 discloses a detection device and a detection method capable of accurately detecting that a battery mounted on a vehicle has been replaced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the detection method described in Patent Document 1, a complex equivalent circuit model is used to detect that the battery has been replaced. For this reason, there are problems such as an increase in the load of the detection process and an increase in the man-hours for conformity. Therefore, there is room for consideration regarding the method for detecting battery replacement.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a battery management device capable of accurately detecting, by a simple method, that the battery has been replaced, etc.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the disclosed technology is a battery management device for managing a battery mounted on a vehicle, comprising: an acquisition unit that acquires data including information on the current of the battery and information on the start of the vehicle from the vehicle; a derivation unit that derives, based on the data, an integrated value of the current by which the battery has been charged and discharged so far, and an average value of the current by which the battery has been charged and discharged during the most recent vehicle startup period; and a determination unit that determines that external charging or replacement of the battery has been performed when the integrated value of the current is less than a first threshold value and the average value of the current is less than a second threshold value.

Effect of the Invention

[0007] According to the battery management device of the present disclosure, it is possible to accurately detect that the battery has been externally charged or the battery has been replaced from the integrated value and average value of the current by which the battery has been charged and discharged, which can be easily obtained, without using a complex equivalent circuit model that increases the load of the detection process.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10A

Figure 10B

Figure 10C

Mode for Carrying Out the Invention

[0009] The battery management device of the present disclosure uses battery state such as the integrated value of the charge and discharge current of the battery, the average value of the charge and discharge current, and the starting voltage that can be easily obtained from the battery, and based on the change or deviation tendency of the battery state, etc., it detects that the battery has been externally charged or the battery has been replaced. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [Configuration] FIG. 1 is a block diagram showing a schematic configuration of a battery management system 1 including a battery management device 20 according to an embodiment of the present disclosure. The battery management system 1 illustrated in FIG. 1 includes a vehicle 10 and a battery management device 20 in its configuration.

[0011] (1) Vehicle Vehicle 10 is communicably connected to battery management device 20. This vehicle 10 is, for example, an automobile, and includes at least a battery 11, a battery information acquisition unit 12 built into the battery 11, and a data transmission unit 13. Note that in FIG. 1, an example is shown in which there is one vehicle 10 communicably connected to battery management device 20, but a plurality of vehicles 10 may each be communicably connected to battery management device 20.

[0012] The battery 11 is a rechargeable secondary battery such as a lithium ion battery or a lead storage battery, for example. As the battery 11, an auxiliary battery can be exemplified. This battery 11 may be charged, for example, via direct connection with a jumper cable or the like from an external charger. Also, when the battery 11 deteriorates, it is replaced with a new one.

[0013] The battery information acquisition unit 12 acquires battery information regarding the state of the battery 11. The battery information includes the voltage, current (charging current, discharging current), and temperature of the battery 11, etc. These battery information can be detected using detection elements (voltage sensors, current sensors, temperature sensors, etc.) (not shown) provided in the battery 11 or the like. Note that the battery information acquisition unit 12 does not have to be built into the battery 11 and may be configured outside the battery 11.

[0014] In the present embodiment, the charging current flowing into the battery 11 for charging is set as a positive value, the discharging current flowing out of the battery 11 for discharging is set as a negative value, and the current integrated value obtained by adding the charging current and the discharging current is defined as the charge-discharge amount of the battery 11. This charge-discharge amount is defined as "0 (zero)" when the battery 11 maintains a fully charged state (SOC = 100%), and is expressed as a negative value smaller than zero according to the remaining capacity of the battery 11.

[0015] The data transmission unit 13 is configured to have a function of controlling communication between the vehicle 10 and the battery management device 20. The data transmission unit 13 transmits data including the battery information acquired by the battery information acquisition unit 12 and information related to the startup of the vehicle 10 to the battery management device 20. Examples of the information related to the startup of the vehicle 10 include the timing when the vehicle 10 starts (when IG-ON) and the period during which the vehicle 10 is starting (the time from the start of startup to the end of startup). This data transmission unit 13 is realized by, for example, a data communication module (DCM).

[0016] (2) Battery management device The battery management device 20 is communicably connected to the vehicle 10. This battery management device 20 is, for example, a server on the cloud, and includes at least a data reception unit 21, an external charging / exchange detection unit 22, and a data output unit 23.

[0017] The data reception unit 21 is configured to have a function of controlling communication between the battery management device 20 and the vehicle 10. This data reception unit 21 can receive data transmitted from the vehicle 10.

[0018] The external charging / exchange detection unit 22 is a configuration for detecting that the battery 11 has been externally charged or the battery 11 has been exchanged based on the data (battery information, startup information) received by the data reception unit 21. Details of the detection method performed by this external charging / exchange detection unit 22 will be described later.

[0019] When the external charging / exchange detection unit 22 detects that the battery 11 has been externally charged or the battery 11 has been exchanged, the data output unit 23 can output the fact that the detection has been made. Examples of the output destination include the user of the vehicle 10 and the dealer.

[0020] [Control] Next, with further reference to FIGS. 2 to 9, the control performed by the battery management device 20 according to the present embodiment will be described. Note that the control described below is executed by the battery management device 20 for each vehicle 10.

[0021] (1) First Embodiment FIG. 2 is a flowchart for explaining the processing procedure of a first embodiment of battery replacement determination control executed by the battery management device 20. This first embodiment is a method that utilizes the state of the battery 11 during vehicle travel. The battery replacement determination control illustrated in FIG. 2 is repeatedly started, for example, each time the ignition of the vehicle 10 is turned on (IG-ON) and the vehicle 10 starts.

[0022] (Step S201) The data reception unit 21 receives data transmitted from the data transmission unit 13 of the vehicle 10. The data received by the data reception unit 21 includes at least information regarding the current of the battery 11 and information regarding the startup of the vehicle 10. This received data may be stored in a predetermined storage unit (not shown). When the data is received by the data reception unit 21, the process proceeds to step S202.

[0023] (Step S202) The external charging / exchange detection unit 22 updates (derives) the current integration value of the battery 11. Specifically, the external charging / exchange detection unit 22 calculates the charge / discharge amount (current value) of the battery 11 from the previous startup to the current startup based on the current of the battery 11 (current value) included in the data received in step S201, and adds the calculated charge / discharge amount (current value) to the current integration value of the battery 11 obtained by integrating all the previous charge / discharge amounts (past values). When the current integration value of the battery 11 is updated by the external charging / exchange detection unit 22, the process proceeds to step S203.

[0024] The integrated current value of the battery 11 derived in this step S202 indicates that if the absolute value of the negative value is small, as shown in the lower diagram of FIG. 3, the battery 11 is close to being fully charged, and if the absolute value of the negative value is large, the battery 11 is far from being fully charged. FIG. 3 shows an image diagram of the integrated current value of the battery 11. This integrated current value should originally approach full charge like a dotted line after the replacement of the battery 11, but it decreases like a solid line if the replacement cannot be recognized by a sensor or the like. In the present embodiment, such misrecognition is eliminated.

[0025] (Step S203) Based on the data received in the above step S201, the external charging / exchange detection unit 22 determines whether the period during which the vehicle 10 is started (the time from the start of startup to the end of startup) exceeds a predetermined time TD (fourth threshold value). This determination is made to determine whether sufficient charging has been performed. Therefore, the necessary time for determining that the battery 11 has reached the fully charged state is set for the predetermined time TD. When the external charging / exchange detection unit 22 determines that the vehicle startup period exceeds the time TD (step S203, yes), the process proceeds to step S204. On the other hand, when the external charging / exchange detection unit 22 determines that the vehicle startup period is equal to or less than the time TD (step S203, no), the process proceeds to step S206.

[0026] (Step S204) The external charging / exchange detection unit 22 derives the average current value of the battery 11. Specifically, based on the data received in the above step S201, the external charging / exchange detection unit 22 derives the average value of the current by which the battery 11 is charged and discharged during the most recent startup period of the vehicle 10, that is, during the period from the start of the current startup to the end of startup. Since the battery 11 is charged at the rated voltage when mounted on the vehicle 10, if this average current value approaches zero, it indicates that the battery 11 is close to being fully charged, and if the value is large, it indicates that the battery 11 is not fully charged. When the external charging / exchange detection unit 22 derives the average current value of the battery 11, the process proceeds to step S205.

[0027] An image diagram of the average current value of the battery 11 derived in this step S204 is shown in the lower diagram of FIG. 4. As shown in FIG. 4, the average current value of the battery 11 is the average value of the current during the vehicle startup period including startup. If the above-mentioned time TD is short, the influence of the charging current of the battery 11 after startup becomes large, and the average current value will be pushed up. Therefore, it is desirable to set the time TD to a time at which the influence of the current fluctuation after startup can be sufficiently ignored.

[0028] (Step S205) The external charging / exchange detection unit 22 determines whether the integrated current value of the battery 11 is less than a predetermined integrated value Ahe (first threshold value) and whether the average current value of the battery 11 is greater than zero and less than a predetermined current value Ice (second threshold value). This determination is made to determine whether there is a contradiction between the integrated current value and the average current value with respect to the state of charge of the battery 11. Any value (for example, "-10 Ah") equal to or greater than the integrated current value that can be obtained when the battery 11 is in a state near full charge is set as the integrated value Ahe. Also, any value (for example, "2.5 A") greater than the current that can be obtained when the battery 11 is in a state near full charge is set as the current value Ice. The integrated value Ahe and the current value Ice are appropriately set based on the capacity and performance of the battery 11, the specifications required for the vehicle 10, and the like. When the external charging / exchange detection unit 22 determines that the integrated current value of the battery 11 is less than the integrated value Ahe and the average current value of the battery 11 is greater than zero and less than the current value Ice (step S205, yes), the process proceeds to step S206. On the other hand, when the external charging / exchange detection unit 22 determines that the integrated current value of the battery 11 is greater than or equal to the integrated value Ahe, or the average current value of the battery 11 is less than or equal to zero, or greater than or equal to the current value Ice (step S205, no), the process proceeds to step S207.

[0029] (Step S206) The external charging / exchange detection unit 22 increments by one a determination count X for counting the number of times the determination in step S205 is "true". Note that this determination count X is cleared when parameters used in other logics for determining, for example, the charging state of the battery 11, etc., which are based on the determination that there has been external charging or replacement of the battery 11, are reset. When the determination count X is incremented by one by the external charging / exchange detection unit 22, the process proceeds to step S207.

[0030] (Step S207) The external charging / exchange detection unit 22 determines whether the determination count X exceeds a predetermined number ct1 (third threshold value). This determination is made to avoid false detection due to the influence of noise, etc., and the predetermined number ct1 is set to an arbitrary value (e.g., "5 times") that can enhance the determination accuracy. When the external charging / exchange detection unit 22 determines that the determination count X exceeds the number ct1 (step S207, yes), the process proceeds to step S208. On the other hand, when the external charging / exchange detection unit 22 determines that the determination count X is less than or equal to the number ct1 (step S207, no), the process proceeds to step S209.

[0031] (Step S208) The external charging / exchange detection unit 22 turns on a detection flag indicating that it has detected external charging or replacement of the battery 11. In response to this detection flag being turned on, the data output unit 23 can perform necessary processing. When the detection flag is turned on by the external charging / exchange detection unit 22, this battery replacement etc. determination control ends.

[0032] (Step S209) The external charging / exchange detection unit 22 turns off the detection flag indicating that it has detected external charging or replacement of the battery 11. When the detection flag is turned off by the external charging / exchange detection unit 22, this battery replacement etc. determination control ends.

[0033] The battery replacement determination control of the first embodiment described above utilizes the phenomenon that the charging current decreases when the battery 11 reaches a fully charged state (SOC = 100%) during the running of the vehicle 10. If the integrated current value during running is less than the first threshold and the number of times the average current value is less than the second threshold exceeds the third threshold state, it is determined that the battery 11 has been externally charged or replaced. By this method, external charging or replacement of the battery 11 can be easily detected without using the voltage that fluctuates due to external disturbances.

[0034] (2) Second Embodiment FIG. 5A and FIG. 5B are flowcharts for explaining the processing procedure of the second embodiment of the battery replacement determination control executed by the battery management device 20. This second embodiment specializes in the SOC dependence of the voltage of the battery 11 and uses a method that utilizes the direction of the starting voltage change and the direction of the integrated current value change. The processing in FIG. 5A and the processing in FIG. 5B are respectively connected by connectors M and N. The battery replacement determination control illustrated in FIG. 5 is repeatedly started each time the ignition of the vehicle 10 is turned on (IG-ON) and the vehicle 10 starts.

[0035] (Step S501) The data reception unit 21 receives the data transmitted from the data transmission unit 13 of the vehicle 10. The data received by the data reception unit 21 at least includes information regarding the current and voltage of the battery 11. This received data may be stored in a predetermined storage unit (not shown). When the data is received by the data reception unit 21, the processing proceeds to step S502.

[0036] (Step S502) The external charging and swapping detection unit 22 determines whether the parking time of the vehicle 10 before receiving data in step S501 above is equal to or longer than a predetermined time (seventh threshold value). That is, the external charging and swapping detection unit 22 determines whether the time elapsed from the end of the previous startup of the vehicle 10 to the current startup is equal to or longer than the predetermined time. This determination is made to determine whether the starting voltage of the battery 11 is affected by polarization. When the external charging and swapping detection unit 22 determines that the parking time of the vehicle 10 is equal to or longer than the predetermined time (step S502, Yes), the process proceeds to step S503. On the other hand, when the external charging and swapping detection unit 22 determines that the parking time of the vehicle 10 is less than the predetermined time (step S502, No), the process proceeds to step S508.

[0037] (Step S503) The external charging and swapping detection unit 22 updates (derives) the current integration value of the battery 11. Specifically, the external charging and swapping detection unit 22 calculates the charge and discharge amount (current value) of the battery 11 from the previous startup to the current startup based on the current of the battery 11 (current value) included in the data received in step S501 above, and adds the calculated charge and discharge amount (current value) to the current integration value of the battery 11 obtained by integrating all the previous charge and discharge amounts (past values). When the current integration value of the battery 11 is updated by the external charging and swapping detection unit 22, the process proceeds to step S504.

[0038] (Step S504) The external charging and swapping detection unit 22 derives the difference value of the starting voltage of the battery 11. Specifically, the external charging and swapping detection unit 22 derives a first voltage difference (= current value - previous value), which is the difference value between the starting voltage of the battery 11 at the current startup (current value) and the starting voltage of the battery 11 at the previous startup (previous value), based on the data received in step S501 above. When the difference value of the starting voltage is derived by the external charging and swapping detection unit 22, the process proceeds to step S505.

[0039] An image diagram of the difference value of the starting voltage of the battery 11 derived in this step S504 is shown in the upper diagram of FIG. 6. As shown in FIG. 6, the difference value (first voltage difference) of the starting voltage of the battery 11 is the voltage difference between the front and back at each of the actually measured starting voltages of the battery 11.

[0040] Here, it is desirable to use a corrected value obtained by excluding the variation factors due to temperature, current, and polarization from the actually measured value as the starting voltage of the battery 11 used for deriving the first voltage difference. As shown in the following formula 1, the variation factor due to temperature can be excluded by adding to the actually measured value of the starting voltage of the battery 11 a value obtained by multiplying the coefficient A based on the starting voltage at 25 degrees, which is the reference temperature, by the difference between 25 degrees and the actually measured temperature. Also, as shown in the following formula 2, the variation factor due to current can be further excluded by adding to the starting voltage of the battery 11 after temperature correction a value obtained by multiplying the coefficient B based on the starting voltage at 40 amperes, which is the reference starting current, by the difference between 40 amperes and the actually measured current. Further, regarding the variation factor due to polarization, it can be excluded by using the starting voltage after the vehicle 10 has been parked for a predetermined time or longer (the process of step S502 above). Temperature-corrected starting voltage = actually measured starting voltage + coefficient A × (25°C - actually measured temperature) … [Formula 1] Current-temperature-corrected starting voltage = temperature-corrected starting voltage + coefficient B × (40A - actually measured current) … [Formula 2]

[0041] (Step S505) The external charging / exchange detection unit 22 derives a voltage conversion value of the difference in the current integration value of the battery 11. Specifically, the external charging / exchange detection unit 22 calculates, based on the current integration value updated in step S503, a difference value (= current value - previous value) between the integrated value of the current (current value) by which the battery 11 has been charged and discharged until the current startup and the integrated value of the current (previous value) by which the battery 11 has been charged and discharged until the previous startup, and derives a second voltage difference which is a value obtained by converting the calculated difference into voltage. This conversion is performed by dividing the difference value of the current integration value by a predetermined coefficient (for example, "10") that converts the change amount of the current integration value into the change amount of the voltage. When the voltage conversion value of the difference in the current integration value is derived by the external charging / exchange detection unit 22, the process proceeds to step S506.

[0042] An image diagram of the difference value of the current integration value of the battery 11 derived in this step S505 is shown in the lower diagram of FIG. 6. As shown in FIG. 6, the difference value (before voltage conversion) of the current integration value of the battery 11 is the difference in the current integration value before and after each of the current integration values of the battery 11. This difference in the current integration value is converted into a voltage value by a coefficient. Note that the difference value of the current integration value of the battery 11 before this voltage conversion is the same value as the charge / discharge amount (current value) of the battery 11 from the previous startup to the current startup, which was used for updating the current integration value of the battery 11 in step S503.

[0043] (Step S506) The external charging / exchange detection unit 22 determines whether a value obtained by subtracting a second voltage difference, which is a voltage conversion value of a difference in current integration value, from a first voltage difference, which is a difference value of the starting voltage of the battery 11, is greater than a predetermined voltage value dVce (fifth threshold). This determination is made to determine whether there is a contradiction between the first voltage difference and the second voltage difference in which the change directions are the same. A value greater than zero (for example, "2") is set for the voltage value dVce in order to avoid false determination due to voltage variation. When the external charging / exchange detection unit 22 determines that the value obtained by subtracting the second voltage difference from the first voltage difference is greater than the voltage value dVce (step S506, yes), the process proceeds to step S507. On the other hand, when the external charging / exchange detection unit 22 determines that the value obtained by subtracting the second voltage difference from the first voltage difference is equal to or less than the voltage value dVce (step S506, no), the process proceeds to step S508.

[0044] (Step S507) The external charging / exchange detection unit 22 increments by one a determination count Y for counting the number of times the determination in step S506 is "true". Note that this determination count Y is cleared by resetting a parameter used in other logic for determining, for example, the rise of the battery 11, based on the determination that there has been external charging or replacement of the battery 11. When the determination count Y is incremented by one by the external charging / exchange detection unit 22, the process proceeds to step S508.

[0045] (Step S508) The external charging / exchange detection unit 22 determines whether the determination count Y exceeds a predetermined count ct2 (sixth threshold value). This determination is made to avoid false detection due to the influence of noise or the like, and the predetermined count ct2 is set to an arbitrary value (for example, "five times") that can improve the determination accuracy. Note that this count ct2 may be the same value as the count ct1 described in the first embodiment or a different value. When the external charging / exchange detection unit 22 determines that the determination count Y exceeds the count ct2 (step S508, yes), the process proceeds to step S509. On the other hand, when the external charging / exchange detection unit 22 determines that the determination count Y is less than or equal to the count ct2 (step S508, no), the process proceeds to step S510.

[0046] (Step S509) The external charging / exchange detection unit 22 turns on a detection flag indicating that external charging or exchange of the battery 11 has been detected. In response to this detection flag being turned on, the data output unit 23 can perform necessary processing. When the detection flag is turned on by the external charging / exchange detection unit 22, the battery replacement determination control ends.

[0047] (Step S510) The external charging / exchange detection unit 22 turns off a detection flag indicating that external charging or exchange of the battery 11 has been detected. When the detection flag is turned off by the external charging / exchange detection unit 22, the battery replacement determination control ends.

[0048] The battery replacement determination control of the second embodiment described above focuses on the direction of the change in the starting voltage and the direction of the change in the current integration value of the battery 11, and if the deviation between the difference value of the starting voltage of the battery 11 (first voltage difference) and the voltage conversion value of the difference in the current integration value (second voltage difference) is greater than the fifth threshold value, it is determined that the battery 11 has been externally charged or exchanged. By this method, it is possible to easily detect external charging or exchange of the battery 11 while suppressing the influence of external disturbances on the voltage and eliminating the influence of integration errors on the current integration value.

[0049] (3) Third Embodiment FIG. 7 is a flowchart for explaining the processing procedure of a third embodiment of battery replacement determination control executed by the battery management device 20. This third embodiment is a method using the moving average value of the starting voltage. The battery replacement determination control illustrated in FIG. 7 is repeatedly started, for example, every time the ignition of the vehicle 10 is turned on (IG-ON) and the vehicle 10 starts.

[0050] (Step S701) The data reception unit 21 receives the data transmitted from the data transmission unit 13 of the vehicle 10. The data received by the data reception unit 21 at least includes information regarding the current and voltage of the battery 11. This received data may be stored in a predetermined storage unit (not shown). When the data is received by the data reception unit 21, the process proceeds to step S702.

[0051] (Step S702) The external charging / exchange detection unit 22 updates (derives) the current integration value of the battery 11. Specifically, the external charging / exchange detection unit 22 calculates the charge / discharge amount (current value) of the battery 11 from the previous start-up to the current start-up based on the current (current value) of the battery 11 included in the data received in step S701, and adds the calculated charge / discharge amount (current value) to the current integration value of the battery 11 obtained by integrating all the previous charge / discharge amounts (past values). When the current integration value of the battery 11 is updated by the external charging / exchange detection unit 22, the process proceeds to step S703.

[0052] (Step S703) The external charging / exchange detection unit 22 derives a moving average coefficient α1 used for updating the voltage reference value. The voltage reference value (VEMA1) is a value of voltage that is sequentially updated using the moving average coefficient α1 calculated in this step S703, with the predetermined voltage of the battery 11 as the initial voltage. Examples of the initial voltage include the voltage of the new battery 11 and the voltage when fully charged by an external charger. The moving average coefficient α1 is a coefficient that changes according to the difference value between the starting voltage of the battery 11 at the current startup and the voltage reference value updated at the previous startup. For example, as shown in FIG. 8, it can be a value that decreases exponentially according to the increase in the difference value. This moving average coefficient α1 may be extracted from a data map like FIG. 8 or calculated by a predetermined arithmetic formula. When the external charging / exchange detection unit 22 derives the moving average coefficient α1, the process proceeds to step S704.

[0053] (Step S704) The external charging / exchange detection unit 22 updates (derives) the voltage reference value. Specifically, the external charging / exchange detection unit 22 updates the voltage reference value according to the relative difference from the starting voltage of the battery 11 using the moving average coefficient α1 derived in step S703 above, in accordance with the following formula 3. As can be seen from this formula 3, the larger the difference between the voltage reference value and the starting voltage, the smaller the moving average coefficient α1 (FIG. 8), and thus the smaller the voltage change amount of the voltage reference value. Therefore, when the deviation between the voltage reference value and the starting voltage is large, even if an update is performed, the updated voltage reference value will be almost the same as the previous voltage reference value, and the voltage before the update will be substantially retained. When the voltage reference value is updated by the external charging / exchange detection unit 22, the process proceeds to step S705. Updated voltage reference value = (1 - α1) × voltage reference value + α1 × starting voltage …〔Formula 3〕

[0054] (Step S705) The external charging / exchange detection unit 22 derives a moving average coefficient α2 used for updating the voltage reference value. The voltage reference value (VEMA2) is a voltage value that uses the predetermined voltage of the battery 11 as the initial voltage and is sequentially updated using the moving average coefficient α2 calculated in this step S705. The same value as that of the voltage reference value is used for the initial voltage. The moving average coefficient α2 is a coefficient that changes according to the difference value between the starting voltage of the battery 11 at the current startup and the starting voltage of the battery 11 at the previous startup (= current value - previous value). For example, as shown in FIG. 9, it can be a value that decreases exponentially according to the increase in the difference value. Basically, the moving average coefficient α2 is set to a value larger than the above-described moving average coefficient α1. This moving average coefficient α2 may be extracted from a data map such as FIG. 9 or may be calculated by a predetermined arithmetic expression. When the external charging / exchange detection unit 22 derives the moving average coefficient α2, the process proceeds to step S706.

[0055] (Step S706) The external charging / exchange detection unit 22 updates (derives) the voltage reference value. Specifically, the external charging / exchange detection unit 22 updates the voltage reference value according to the following formula 4 using the moving average coefficient α2 derived in the above step S705. As can be seen from this formula 4, the greater the difference between the previous starting voltage and the current starting voltage, the smaller the moving average coefficient α2 (FIG. 9), and thus the smaller the voltage change amount of the voltage reference value. Therefore, when the starting voltage fluctuates greatly between the previous time and the current time, even if the update is performed, the updated voltage reference value will be almost the same as the previous voltage reference value, and the influence of noise and the like will be removed. When the voltage reference value is updated by the external charging / exchange detection unit 22, the process proceeds to step S707. Updated voltage reference value = (1 - α2) × voltage reference value + α2 × starting voltage … [Formula 4]

[0056] Note that for the starting voltage of the battery 11 used in the above steps S703 to S706, as described in the above second embodiment, it is desirable to use a corrected value obtained by excluding the variation factors due to temperature, current, and polarization from the measured value.

[0057] (Step S707) The external charging / exchange detection unit 22 determines whether the value obtained by subtracting the voltage reference value from the voltage reference value is greater than a predetermined voltage value (eighth threshold value). This determination is made to determine whether there is a contradiction between the voltage reference value and the voltage reference value that change in the same way. The predetermined voltage value can be appropriately set according to the performance of the battery 11 and the required detection performance. In this step S707, it may be simply determined whether the voltage reference value is greater than the voltage reference value without using the predetermined voltage value. When the external charging / exchange detection unit 22 determines that the value obtained by subtracting the voltage reference value from the voltage reference value is greater than the predetermined voltage value (step S707, yes), the process proceeds to step S708. On the other hand, when the external charging / exchange detection unit 22 determines that the value obtained by subtracting the voltage reference value from the voltage reference value is less than or equal to the predetermined voltage value (step S707, no), the process proceeds to step S709.

[0058] (Step S708) The external charging / exchange detection unit 22 turns on the detection flag indicating that external charging or exchange of the battery 11 has been detected. In response to the detection flag being turned on, the data output unit 23 can perform necessary processing. When the detection flag is turned on by the external charging / exchange detection unit 22, the battery replacement determination control ends.

[0059] (Step S709) The external charging / exchange detection unit 22 turns off the detection flag indicating that external charging or exchange of the battery 11 has been detected. When the detection flag is turned off by the external charging / exchange detection unit 22, the battery replacement determination control ends.

[0060] The battery replacement determination control of the third embodiment described above uses the moving average value of the voltage of the battery 11, and if the value obtained by subtracting the voltage reference value from the voltage reference value is greater than a predetermined voltage value, it is determined that the battery 11 has been externally charged or exchanged. By this method, it is possible to easily detect external charging or exchange of the battery 11 while removing the influence of voltage disturbances with a logic using only the voltage value by adjusting the moving average value of the voltage.

[0061] [Application Example] The first, second, and third embodiments of the above-described battery replacement determination control can be executed in appropriate combinations. As an example, the flowcharts of the processing procedures of the battery replacement determination control combining the first and second embodiments are shown in FIGS. 10A, 10B, and 10C. Each process in FIGS. 10A, 10B, and 10C is connected by connectors R and S, respectively.

[0062] Among the processes in the battery replacement determination control of this application example, the processes with the same step numbers as those in FIGS. 2, 5A, and 5B perform the same processes as the first and second embodiments. Hereinafter, the battery replacement determination control of the application example will be described centering on the processes different from the first and second embodiments.

[0063] In FIG. 10A, when the external charging / exchange detection unit 22 determines that the vehicle startup period is less than or equal to time TD (step S203, no), when it is determined in step S205 that the current integration value of the battery 11 is greater than or equal to the integration value Ahe, or the current average value of the battery 11 is less than or equal to zero, or the current value is greater than or equal to Ice (step S205, no), and when the determination count X is incremented by one (step S206), the process proceeds to step S502.

[0064] In FIG. 10B, when the external charging / exchange detection unit 22 determines that the parking time of the vehicle 10 is less than a predetermined time (step S502, no), when it is determined that the value obtained by subtracting the second voltage difference from the first voltage difference is less than or equal to the voltage value dVce (step S506, no), and when the determination count Y is incremented by one (step S507), the process proceeds to step S1001.

[0065] In step S1001 of FIG. 10C, the external charging / exchange detection unit 22 determines whether the determination count X exceeds a predetermined count ct1 (third threshold value) and whether the determination count Y exceeds a predetermined count ct2 (sixth threshold value), respectively. Then, when the external charging / exchange detection unit 22 determines that the determination count X exceeds the count ct1, or when it determines that the determination count Y exceeds the count ct2 (step S1001, yes), the process proceeds to step S208. On the other hand, when the external charging / exchange detection unit 22 determines that the determination count X does not exceed the count ct1 and the determination count Y does not exceed the count ct2 (step S1001, no), the process proceeds to step S209.

[0066] Thus, in the battery replacement determination control of the application example, if the final result (step S1001) is "true" in either the determination based on the first embodiment or the determination based on the second embodiment, it is determined that external charging or replacement of the battery 11 has been performed. As a result, compared to the case where either embodiment is implemented alone, the accuracy of detecting that external charging or replacement of the battery has been performed is improved.

[0067] <Operation and Effect> As described above, according to the battery management device 20 according to an embodiment of the present disclosure, contradictions in the battery state (such as differences in change directions and deviations in values) that occur due to not resetting the parameter of the logic necessary for managing the battery 11 when the battery 11 is externally charged or replaced are determined using information such as the integrated value, average value, and starting voltage of the charge / discharge current of the battery 11 that can be easily obtained.

[0068] By this control, it is possible to accurately detect that the battery 11 has been externally charged or the battery 11 has been replaced without using a complex equivalent circuit model that would increase the processing load.

Industrial Applicability

[0069] The battery management device of the present disclosure can be used when determining that the battery mounted on the vehicle has been externally charged or replaced, etc.

Explanation of Signs

[0070] 1 Battery management system 10 Vehicle 11 Battery 12 Battery information acquisition unit 13 Data transmission unit 20 Battery management device 21 Data reception unit 22 External charging / exchange detection unit 23 Data output unit

Claims

1. A battery management device that manages a battery mounted on a vehicle, an acquisition unit that acquires data including information regarding a current of the battery and information regarding a start of the vehicle from the vehicle; a derivation unit that derives an integrated value of a current that has been charged and discharged by the battery up to now and an average value of a current that has been charged and discharged by the battery during a most recent startup period of the vehicle based on the data; a determination unit that determines that the battery has been externally charged or replaced when the integrated value of the current is less than a first threshold and the average value of the current is less than a second threshold.

2. the derivation unit derives an integrated value of the current and an average value of the current every time the vehicle is started; 2. The battery management device of claim 1, wherein the determination unit determines that the battery has been externally charged or replaced when the number of times that the integrated current value is less than the first threshold value and the average current value is less than the second threshold value exceeds a third threshold value.

3. The battery management device according to claim 1 , wherein the determination unit does not perform the determination when the startup period of the vehicle is less than a fourth threshold value.

4. A battery management device that manages a battery mounted on a vehicle, an acquisition unit that acquires data including information regarding a current and a voltage of the battery from the vehicle when the vehicle is started; a derivation unit that derives, based on the data, a first voltage difference that is a difference between a startup voltage of the battery at the time of the current startup and a startup voltage of the battery at the time of the previous startup, and a second voltage difference that is obtained by converting into voltage a difference between an integrated value of a current that the battery has charged and discharged up to the time of the current startup and an integrated value of a current that the battery has charged and discharged up to the time of the previous startup; a determination unit that determines that the battery has been externally charged or replaced when a value obtained by subtracting the second voltage difference from the first voltage difference exceeds a fifth threshold.

5. 5. The battery management device according to claim 4, wherein the derivation unit converts the current start-up voltage of the battery acquired by the acquisition unit into a start-up voltage at a predetermined reference temperature and reference start-up current of the battery, to derive the first voltage difference.

6. 6. The battery management device of claim 4, wherein the determination unit determines that the battery has been externally charged or replaced when the number of times that the value obtained by subtracting the second voltage difference from the first voltage difference exceeds the fifth threshold value exceeds a sixth threshold value.

7. The battery management device according to claim 4 , wherein the determination unit does not perform the determination when a time period from when the vehicle has finished a previous start-up to when the vehicle is started this time is less than a seventh threshold value.

8. A battery management device that manages a battery mounted on a vehicle, an acquisition unit that acquires data including information regarding a current and a voltage of the battery from the vehicle when the vehicle is started; a derivation unit that derives, based on the data, a voltage reference value that is updated according to a relative difference between a predetermined initial voltage and a startup voltage of the battery at startup, and a voltage reference value that is updated according to a difference between the startup voltage of the battery at the current startup and the startup voltage of the battery at the previous startup; a determination unit that determines that the battery has been externally charged or replaced when a value obtained by subtracting the voltage standard value from the voltage reference value exceeds an eighth threshold.

9. The battery management device of claim 8, wherein the derivation unit derives the voltage reference value such that the amount of voltage change from the previous time to the current time is smaller the greater the difference between the start-up voltage of the battery at the current start-up and the voltage reference value updated at the previous start-up, and derives the voltage reference value such that the amount of voltage change from the previous time to the current time is smaller the greater the difference between the start-up voltage of the battery at the current start-up and the start-up voltage of the battery at the previous start-up.

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