Battery management device, battery management method, and program

Abstract

To provide a battery management device, a method for managing a battery, and a program that can increase the accuracy of estimating an SOC.SOLUTION: A battery management device 100 includes: a voltage measuring unit 102 for repeatedly measuring the voltage of a battery from when the usage of the battery is ended to when the usage of the battery is resumed; an open circuit voltage estimation unit 104 for estimating an open circuit voltage by using a shift of change in the measured voltage; and a charged state estimation unit 106 for estimating an SOC (state of charge) showing the charged state of the battery or the amount of change (▵SOC) of SOC by using the estimated open circuit voltage.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] An example of a technique for estimating the state of charge of a battery is described in Patent Document 1. The state of charge estimation device of Patent Document 1 includes a voltage detection unit that detects the voltage of the battery, a calculation unit that calculates, as an upper limit value, the state of charge of the battery corresponding to the closed-circuit voltage detected by the voltage detector during charging of the battery, an estimation unit that estimates the open-circuit voltage at the time of decomposition and dissipation of the battery and estimates the state of charge of the battery based on the estimated open-circuit voltage, and a selection unit that, when the state of charge estimated by the estimation unit is less than or equal to the upper limit value during charging and discharging stop of the battery, selects the state of charge estimated by the estimation unit as the state of charge of the battery, and when the state of charge estimated by the estimation unit is greater than the upper limit value, selects the upper limit value as the state of charge of the battery. With this configuration, a decrease in the estimation accuracy of the state of charge of the battery after charging and discharging stop is suppressed.

[0003] Also, Patent Documents 2 and 3 also describe techniques for accurately obtaining the remaining capacity of the power storage device and performing state detection.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology described in Patent Document 1 mentioned above, only the SOC (State Of Charge) estimated during charging is set as the upper limit value, and the SOC during startup is not corrected. Further, in the technology described in Patent Document 2, reference data or reference functions are used for the estimation of SOC, and in the technology described in Patent Document 3, it is necessary to perform charge control for the estimation of OCV. Therefore, there is a problem that the load of the estimation process of OCV and SOC and the burden on the battery increase.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a battery management device, a battery management method, and a program that improve the estimation accuracy of SOC with a simple process that also reduces the burden on the battery.

Means for Solving the Problems

[0007] According to one aspect of the present invention, after the battery has been used up, voltage measuring means for repeatedly measuring the voltage of the battery between the end of use of the battery and the resumption of use of the battery; open circuit voltage estimating means for estimating an open circuit voltage using the transition of the change in the measured voltage; charge state estimating means for estimating a SOC (State Of Charge) indicating the charge state of the battery or a change amount (△SOC) of the SOC using the estimated open circuit voltage, a battery management device is provided.

[0008] According to one aspect of the present invention, one or more computers after the battery has been used up, repeatedly measure the voltage of the battery between the end of use of the battery and the resumption of use of the battery, estimate an open circuit voltage using the transition of the change in the measured voltage, estimate a SOC (State Of Charge) indicating the charge state of the battery or a change amount (△SOC) of the SOC using the estimated open circuit voltage, a battery management method is provided.

[0009] According to one aspect of the present invention, Cause a computer to After the battery has been used up, repeatedly measure the voltage of the battery until the battery is restarted. Estimate the open circuit voltage using the trend of the change in the measured voltage. A program is provided for causing a computer to execute a procedure for estimating the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open circuit voltage.

[0010] As another aspect of the present invention, it may be a program for causing at least one computer to execute the method of the above aspect, or it may be a computer-readable recording medium on which such a program is recorded. This recording medium includes a non-temporary tangible medium. This computer program includes computer program code for causing a computer to implement the battery management method on a battery management device when executed by the computer.

[0011] Any combination of the above components, and those obtained by converting the expression of the present invention among methods, devices, systems, recording media, computer programs, etc., are also effective as aspects of the present invention.

[0012] In addition, the various components of the present invention do not necessarily have to exist independently of each other. It is also possible that a plurality of components are formed as one member, one component is formed of a plurality of members, a certain component is part of another component, and a part of a certain component overlaps with a part of another component, etc.

[0013] Also, although a plurality of procedures are described in order in the method and computer program of the present invention, the described order does not limit the order of executing the plurality of procedures. Therefore, when implementing the method and computer program of the present invention, the order of the plurality of procedures can be changed within a range where there is no problem in content.

[0014] Furthermore, the plurality of procedures of the method and computer program of the present invention are not limited to being executed at individually different timings. For this reason, other procedures may occur during the execution of a certain procedure, or a part or all of the execution timing of a certain procedure and the execution timing of other procedures may overlap, and so on.

Advantages of the Invention

[0015] According to one aspect of the present invention, it is possible to provide a battery management device, a battery management method, and a program that improve the estimation accuracy of SOC with a simple process that also places a light burden on the battery.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are denoted by similar reference numerals, and the description thereof will be omitted as appropriate. In addition, in each of the following figures, the configuration of parts not related to the essence of the present invention is omitted and not shown.

[0018] In the embodiment, "acquisition" includes at least one of the following: the self-device going to obtain data or information stored in another device or storage medium (active acquisition), and the self-device inputting data or information output from another device (passive acquisition). Examples of active acquisition include requesting or inquiring another device and receiving its reply, and accessing and reading another device or storage medium. Examples of passive acquisition include receiving information distributed (or transmitted, push-notified, etc.). Furthermore, "acquisition" may mean selecting and acquiring from the received data or information, or selecting and receiving the distributed data or information.

[0019] (First Embodiment) <Minimum Configuration Example> FIG. 1 is a diagram showing an overview of a battery management device 100 according to an embodiment. The battery management device 100 includes a voltage measurement unit 102, an open circuit voltage estimation unit 104, and a state of charge estimation unit 106. The voltage measurement unit 102 repeatedly measures the voltage of the battery after the end of battery use until the restart of battery use. The open circuit voltage estimation unit 104 estimates the open circuit voltage (OCV: Open Circuit Voltage) using the transition of the measured voltage change. The state of charge estimation unit 106 estimates the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated OCV.

[0020] <Operation Example> FIG. 2 is a flowchart showing an operation example of the battery management device 100 according to the present embodiment. The flow of the battery management device 100 mainly includes two processes: a voltage measurement process P100 and a SOC estimation process P110. The voltage measurement process P100 repeats the operation during the period when the battery is left unattended. First, in the voltage measurement process P100, after the battery is used up (YES in step S101) and until the battery use is restarted (NO in step S105), the voltage measurement unit 102 repeatedly measures the voltage of the battery (step S103). For example, in the case of a vehicle-mounted battery, when the ignition key is turned off, that is, when the engine is stopped, the voltage measurement process P100 starts. That is, while the vehicle engine is running (NO in step S101), this flow does not start.

[0021] Next, when the battery use is restarted (YES in step S105), the SOC estimation process P110 starts. For example, in the case of a vehicle-mounted battery, when the ignition key is turned on, that is, when the engine is started, the SOC estimation process P110 starts. The open circuit voltage estimation unit 104 estimates the open circuit voltage (OCV) using the transition of the measured voltage change (step S111). Then, the state of charge estimation unit 106 estimates the state of charge (SOC) indicating the charge state of the battery or the change amount (ΔSOC) of the SOC using the estimated OCV (step S113).

[0022] According to this battery management device 100, the voltage measurement unit 102 repeatedly measures the voltage of the battery after the battery is used up and until the battery use is restarted. The open circuit voltage estimation unit 104 estimates the OCV using the transition of the measured voltage change, and the state of charge estimation unit 106 estimates the SOC indicating the charge state of the battery or the change amount (ΔSOC) of the SOC using the estimated OCV. According to this configuration, the battery management device 100 can improve the estimation accuracy of the SOC with a simple process that also places a light burden on the battery.

[0023] Hereinafter, a detailed example of the battery management device 100 will be described.

[0024] (Second Embodiment) <System Overview> FIG. 3 is a diagram conceptually showing the system configuration of the battery management system 1 of the embodiment. The battery management system 1 of the embodiment is a system that manages the battery 10 mounted on the vehicle 5. However, the battery 10 is not limited to being mounted on the vehicle 5. The battery management device 100 of the embodiment estimates the SOC (State Of Charge) indicating the charge state of the battery 10, which is used for calculating the SOH (State of health), an index indicating the soundness of the battery 10.

[0025] The battery 10 is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The battery 10 is a battery module including a plurality of cells. The battery 10 may be mounted on the vehicle 5 as a package including the BMS (Battery Management System) 20 and a protection circuit, a charge / discharge control circuit, a cooling mechanism, etc., not shown.

[0026] The battery management device 100 is, for example, the BMS 20. In another example, the battery management device 100 may be realized by an information processing device 200 capable of communicating with the battery module. Alternatively, the battery management device 100 may be realized by a combination of the BMS 20 and the information processing device 200.

[0027] The information processing device 200 is connected to the BMS 20 of the battery 10 via the communication network 3. The information processing device 200 is a computer such as a personal computer or a server computer. The information processing device 200 includes a storage device 220. The storage device 220 may be provided inside or outside the information processing device 200. That is, the storage device 220 may be hardware integrated with the information processing device 200 or hardware separate from the information processing device 200.

[0028] Since the state of charge (SOC) of the battery 10 decreases with respect to the initial full charge as the battery 10 is used, it is necessary to estimate the SOC according to the usage state. As one of the methods for estimating this SOC, there is a method based on the estimation of the open circuit voltage (OCV: Open Circuit Voltage).

[0029] The state of charge estimation unit 106 estimates this SOC based on the OCV estimated from the voltage value during the standby period from the end of the use of the battery 10 until the restart of use, using an SOC-OCV map that associates the OCV with the SOC. The voltage value of the battery 10 is the voltage value between the positive terminal and the negative terminal of the battery 10. Also, for the calculation of the state of health (SOH), the ΔSOC between the SOC at the start of the previous use of the battery 10 and the SOC at the start of the current use, and the capacity (Ah) used in the previous use are used. On the other hand, the voltage of the battery 10 during the standby period includes polarization depending on the load state during the running of the vehicle 5 or during the charging of the battery 10. Therefore, during the standby period, since the voltage of the battery 10 fluctuates before the start of polarization, an accurate OCV cannot be estimated.

[0030] FIG. 4 is a diagram showing the voltage change of the battery 10 during the standby period. After the ignition key of the vehicle 5 is turned off, the voltage value V of the battery 10 decreases, and gradually the change amount ΔV becomes smaller and the change stops. Since the voltage value V before the start of polarization fluctuates, in the case before relaxation, the relaxed OCV is estimated based on the voltage transition during the standby period.

[0031] <Hardware configuration example> FIG. 5 is a block diagram illustrating the hardware configuration of a computer 1000 that realizes the battery management device 100 of FIG. 1. The information processing device 200 and the BMS 20 of FIG. 3 are also realized by the computer 1000. As described above, the functions of the battery management device 100 may be realized by the BMS 20 and the information processing device 200 sharing the work.

[0032] Computer 1000 has a bus 1010, a processor 1020, a memory 1030, a storage device 1040, an input / output interface 1050, and a network interface 1060.

[0033] Bus 1010 is a data transmission path for the processor 1020, the memory 1030, the storage device 1040, the input / output interface 1050, and the network interface 1060 to send and receive data from each other. However, the method of connecting the processor 1020 and the like to each other is not limited to bus connection.

[0034] Processor 1020 is a processor realized by a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or the like.

[0035] Memory 1030 is a main storage device realized by a RAM (Random Access Memory) or the like.

[0036] Storage device 1040 is an auxiliary storage device realized by an HDD (Hard Disk Drive), an SSD (Solid State Drive), a memory card, a ROM (Read Only Memory), or the like. Storage device 1040 stores program modules that implement each function of battery management device 100 (for example, voltage measurement unit 102, open circuit voltage estimation unit 104, state of charge estimation unit 106, acquisition unit 108 described later, etc.). By the processor 1020 loading these program modules onto the memory 1030 and executing them, each function corresponding to the program module is realized. Further, the storage device 1040 may also store each data of the battery management device 100 and each data of the storage device 220 of the information processing device 200.

[0037] The program module may be recorded on a recording medium. The recording medium for recording the program module includes a non-transitory tangible medium that can be used by the computer 1000, and program code readable by the computer 1000 (processor 1020) may be embedded in the medium.

[0038] The input / output interface 1050 is an interface for connecting the computer 1000 and various input / output devices. The input / output interface 1050 also functions as a communication interface for performing short-range wireless communication such as Bluetooth (registered trademark) and NFC (Near Field Communication).

[0039] The network interface 1060 is an interface for connecting the computer 1000 to a communication network. This communication network is, for example, a LAN (Local Area Network) or a WAN (Wide Area Network). The method by which the network interface 1060 connects to the communication network may be a wireless connection or a wired connection. However, when the battery management device 100 is realized by the information processing device 200 and the battery 10 is mounted on the vehicle 5, the connection to the communication network 3 is a wireless connection.

[0040] And the computer 1000 is connected to necessary devices (for example, a voltmeter, an ammeter, various sensors not shown, a keyboard, a mouse, a display, a speaker, a microphone, a printer, etc. of the information processing device 200 not shown) via the input / output interface 1050 or the network interface 1060.

[0041] Each component of the battery management device 100 in FIG. 1 and the embodiments of FIG. 10 described below is realized by any combination of the hardware and software of the computer 1000 in FIG. 5. And it is understood by those skilled in the art that there are various modifications to the realization method and apparatus. The functional block diagram showing the battery management device 100 of each embodiment shows blocks of logical functional units, not the configuration in hardware units.

[0042] <Functional configuration example> Hereinafter, a functional configuration example of the battery management device 100 according to the embodiment will be described with reference to FIG. 1. After the battery 10 has been used up and until the battery 10 is restarted, the voltage measurement unit 102 repeatedly measures the voltage of the battery 10 during the standby period. When acquiring the voltage, the voltage measurement unit 102 activates the BMS 20 to acquire the voltage, and then returns the BMS 20 to the sleep state. The timing of returning to the sleep state may be after operations such as acquisition of the voltage V, calculation of the voltage change amount ΔV, and saturation determination processing are completed. The voltage value acquired by the voltage measurement unit 102 is stored in the memory 1030 or the storage device 1040 before entering the sleep state.

[0043] FIG. 6 is a diagram showing an example of the data structure of the measurement result information 300 stored in at least one of the memory 1030, the storage device 1040, and the storage device 220. The measurement result information 300 includes the date and time when the voltage measurement unit 102 acquired the measurement value, the measured value of the voltage, the voltage change amount, and the saturation determination result. However, the measurement result information 300 includes at least the measurement date and time and the measured value of the voltage.

[0044] The standby period of the battery 10 is the period from when the ignition key of the vehicle 5 is turned off, that is, when the engine of the vehicle 5 is turned off, to when the ignition key of the vehicle 5 is turned on, that is, when the engine of the vehicle 5 is started.

[0045] During the standby period, the BMS 20 starts up periodically by itself, and the voltage measurement unit 102 acquires the voltage from a voltmeter (not shown). The voltage measurement unit 102 acquires the voltage V and further calculates the voltage change amount ΔV. For example, when a predetermined time has elapsed using a sleep counter in the BMS 20, it starts up by itself. Alternatively, an external timer connected to the processor 1020 of the BMS 20 may be used. When the processor 1020 of the BMS 20 shuts down, it starts the timer, and when a predetermined time has elapsed, the timer starts up the BMS 20.

[0046] Alternatively, when the battery management device 100 is realized by the information processing device 200, the information processing device 200 starts up the BMS 20 at the timing of measuring the voltage of the battery 10 and acquires the voltage. The information processing device 200 has a timer (not shown), and when a predetermined time has elapsed using the timer, it starts up the BMS 20. The voltage value acquired by the voltage measurement unit 102 is stored in the storage device 220.

[0047] As shown in FIG. 4, after the battery 10 is used up, the amount of change gradually becomes smaller. Therefore, the voltage measurement unit 102 gradually widens the voltage measurement interval. For example, the measurement interval may be exponentially spaced. For example, the voltage measurement interval is gradually widened from, for example, a 5-minute interval to 10 minutes, 30 minutes, 60 minutes intervals, etc. With this configuration, power saving becomes possible.

[0048] The open circuit voltage estimation unit 104 estimates the OCV using the transition of the measured voltage change. The voltage change amount ΔV per unit time decreases as relaxation progresses. Therefore, the open circuit voltage estimation unit 104 estimates the voltage (OCV) after relaxation by adjusting the voltage change amount ΔV when an infinite time has elapsed.

[0049] The estimation of the OCV is calculated in the following order. (1) Calculate the voltage change amount per unit time. (2) Convert to a logarithm and create an approximation formula by the least squares method from the latest data. However, the approximation formula is not limited to this, and it may not be logarithmically transformed, or it may not be the least squares method. (3) By returning the approximate formula to the real dimension and integrating it, the OCV is estimated.

[0050] The estimation process of the OCV by the open circuit voltage estimation unit 104 is not executed when at least one of the following conditions is satisfied. <Condition 1: Voltage saturation> In the above saturation determination process, the voltage measurement unit 102 determines whether the voltage change amount ΔV is equal to or less than a predetermined small value (V1). When the voltage change amount ΔV becomes the voltage V1, it is determined that saturation has occurred. For example, the state determined to be saturated is after the time point when the voltage becomes V1 in FIG. 4. In this case, the open circuit voltage estimation unit 104 does not perform the OCV estimation process and uses the measured value (closed circuit voltage CCV) as the OCV. Also, when it is determined that saturation has occurred in the saturation determination, the voltage measurement unit 102 may stop measuring the voltage until the next ignition key is turned off.

[0051] <Condition 2: Standby period> When the standby period is shorter than a predetermined time, the open circuit voltage estimation unit 104 does not perform the OCV estimation process, and the OCV maintains the value of the previously estimated OCV.

[0052] The state of charge estimation unit 106 estimates the SOC or ΔSOC indicating the state of charge of the battery using the estimated OCV. As described above, the state of charge estimation unit 106 estimates the SOC from the SOC-OCV map using the estimated OCV during the standby period.

[0053] <Operation example> Hereinafter, the operation of the battery management device 100 according to the embodiment will be described with reference to FIGS. 2 and 7. FIG. 7 is a flowchart showing an operation example of the battery management device 100 according to the embodiment. When the battery management device 100 of the embodiment is in use, from after the end of use of the battery 10 (YES in step S101) to resumption (NO in step S105), the voltage measurement unit 102 acquires the voltage and stores it as measurement result information 300 in at least one of the memory 1030, the storage device 1040, and the storage device 220 (step S103). As described above, in addition to the measured value of the voltage, the measurement result information 300 may store the voltage change amount △V and the saturation determination result.

[0054] When the voltage measurement unit 102 acquires the voltage, it activates the BMS 20 to acquire the voltage, and then returns the BMS 20 to the sleep state. The timing of returning to the sleep state may be after operations such as the acquisition of the OCV and the saturation determination process are completed.

[0055] The voltage measurement unit 102 gradually widens the voltage measurement interval. Also, the voltage measurement unit 102 performs a saturation determination process for the OCV. When the OCV is saturated, the voltage measurement is terminated, and the BMS 20 remains in the sleep state until the use of the battery 10 is resumed.

[0056] When the use of the battery 10 is resumed, that is, when it is detected that the ignition key is turned on, the SOC estimation process P110 in FIG. 7 starts.

[0057] The SOC estimation process P110 in FIG. 7 has steps S121 to S127 in addition to steps S111 and S113 of the SOC estimation process P110 in FIG. 2.

[0058] First, when it is determined in the saturation determination process by the voltage measurement unit 102 that it is saturated (YES in step S121), the open circuit voltage estimation unit 104 does not perform the OCV estimation process, sets the OCV as the CCV (step S123), and proceeds to step S113.

[0059] In the saturation determination process by the voltage measurement unit 102, when it is not determined to be saturated (NO in step S121), the open circuit voltage estimation unit 104 determines whether the rest period is shorter than a predetermined time (step S125). When the rest period is shorter than the predetermined time (YES in step S125), the open circuit voltage estimation unit 104 does not perform the OCV estimation process, and the OCV maintains the previously estimated OCV (step S127), and proceeds to step S113.

[0060] When the rest period is not shorter than the predetermined time (NO in step S125), the open circuit voltage estimation unit 104 proceeds to step S111 and performs the OCV estimation process. The voltage V and the voltage change amount ΔV measured in the voltage measurement process P100 are read and acquired from the measurement result information 300. At this time, the open circuit voltage estimation unit 104 may perform the estimation process using the latest predetermined number (for example, 10) of measurement values.

[0061] However, the voltage saturation determination process based on the rest time in step S125, that is, steps S125 and S127 are not necessarily required.

[0062] As described above, in the battery management device 100 of the present embodiment, the voltage measurement unit 102 repeatedly measures the voltage of the battery after the end of use of the battery until the restart of use of the battery, and the open circuit voltage estimation unit 104 uses the transition of the change in the measured voltage to estimate the OCV, and the state of charge estimation unit 106 uses the estimated OCV to estimate the SOC indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC.

[0063] According to this configuration, the battery management device 100 can improve the estimation accuracy of the SOC with a simple process that also places a light burden on the battery.

[0064] (Third Embodiment) The battery management device 100 of this embodiment is the same as any of the above embodiments, except that it has a configuration to exclude voltage values containing abnormal values from the voltage values used in the estimation process. Since the battery management device 100 of this embodiment has the same configuration as that in FIG. 1, it will be described with reference to FIG. 1. However, the configuration of this embodiment may be combined within a range that does not conflict with at least any one of the configurations of other embodiments.

[0065] When the inflection point of the voltage is detected, the open-circuit voltage estimation unit 104 estimates the OCV using the measured voltage values after the inflection point. However, the measured voltage values after the inflection point may also be used in the estimation process. That is, only the measured value constituting the inflection point may be excluded, and the measured voltage values after the inflection point may also be included and used in the estimation process.

[0066] As shown in FIG. 4, the transition of the value of the voltage V may have an inflection point 30 where the value increases while showing a decreasing trend. In such a case, the open-circuit voltage estimation unit 104 estimates the OCV using the voltage V and the voltage change amount ΔV after the inflection point 30.

[0067] Also, the inflection point detection process by the open-circuit voltage estimation unit 104 may be performed at the timing when the voltage measurement unit 102 acquires the voltage measurement value. For example, when the voltage measurement unit 102 calculates the voltage change amount ΔV, when the calculated voltage change amount ΔV changes from a negative value to a positive value, the voltage V when the voltage change amount ΔV is calculated may be detected as the inflection point. The voltage measurement unit 102 may not store the voltage V and the voltage change amount ΔV in the measurement result information 300. Alternatively, an inflection point flag may be stored in association with the voltage V and the voltage change amount ΔV. The open-circuit voltage estimation unit 104 may refer to the inflection point flag and determine whether the voltage V and the voltage change amount ΔV are inflection points.

[0068] <Operation Example> FIG. 8 is a flowchart showing the main part of the operation example of the battery management device 100 of the embodiment. The flow of this figure is executed before step S111 after the determination in step S125 of the flow of Figure 7 when the elapsed time is not shorter than the predetermined time (NO in step S125). However, in the case of a configuration that does not include step S125 in Figure 7, the flow of this figure is executed before step S111 after the determination in step S121 when it is not determined to be saturated (NO in step S121).

[0069] The open circuit voltage estimation unit 104 determines whether there is an inflection point in the measured voltage value read from the measurement result information 300 (step S131). When an inflection point is detected in the measured voltage value (YES in step S131), the open circuit voltage estimation unit 104 reads and acquires the voltage measurement values after the inflection point from the measurement result information 300 (step S133), and proceeds to step S111. Here, if the measurement values cannot be acquired for the most recent predetermined number of times, the process proceeds to step S127, and the OCV estimation process may not be performed and the previous OCV may be maintained.

[0070] On the other hand, when no inflection point is detected in the measured voltage value (NO in step S131), the open circuit voltage estimation unit 104 reads and acquires the voltage measurement values for the most recent predetermined number of times (for example, 10) from the measurement result information 300 (step S135), and proceeds to step S111.

[0071] Then, in step S111, the open circuit voltage estimation unit 104 estimates the OCV using the voltage measurement values.

[0072] As described above, in the battery management device 100 of the present embodiment, when an inflection point of the voltage is detected, the open circuit voltage estimation unit 104 estimates the OCV using the measured voltage value after the inflection point. That is, when a measured voltage value indicating an abnormal value is detected, it is determined that the measured value was not stable before the measured value, and it cannot be used for the OCV estimation process.

[0073] Thus, according to the battery management device 100 of the present embodiment, it has the same effects as the above embodiment, and furthermore, the estimation accuracy of the OCV can be improved, and thus the estimation accuracy of the SOC can be improved.

[0074] (Fourth Embodiment) The battery management device 100 of the present embodiment is the same as any of the above embodiments except that it has a configuration for controlling the voltage value used in the estimation process when the voltage change amount becomes equal to or less than a reference value. Since the battery management device 100 of the present embodiment has the same configuration as that in FIG. 1, it will be described with reference to FIG. 1. However, the configuration of the present embodiment may be combined within a range that does not conflict with at least any one of the configurations of other embodiments.

[0075] When the voltage change amount ΔV becomes equal to or less than the reference value, the open circuit voltage estimation unit 104 estimates the OCV using the measured value of the voltage before that. The reference value is, for example, a state where the voltage change amount △V has become somewhat stable, for example, the voltage value V0 in FIG. 4. The open circuit voltage estimation unit 104 estimates the OCV using the measured value of the voltage before V0 (included in the range 32 in FIG. 4) when the voltage change amount △V becomes equal to or less than the reference value.

[0076] "When it becomes equal to or less than the reference value" means the time point when the voltage change amount ΔV becomes equal to or less than the reference value in the change over time of the voltage change amount ΔV stored in the measurement result information 300.

[0077] The voltage measurement unit 102 reads and acquires the most recent predetermined number of voltages V and voltage change amounts △V from the measurement result information 300.

[0078] <Operation Example> FIG. 9 is a flowchart showing the main part of the operation example of the battery management device 100 of the embodiment. The flow of this figure is executed before step S111 after the determination in step S125 of the flow of Figure 7 when the storage period is not shorter than a predetermined time (NO in step S125). However, in the case of a configuration that does not include step S125 in Figure 7, the flow of this figure is executed before step S111 after the determination in step S121 when it is not determined to be saturated (NO in step S121).

[0079] The open-circuit voltage estimation unit 104 determines whether the voltage change amount ΔV read from the measurement result information 300 is less than or equal to a reference value (step S141). When the voltage change amount ΔV is less than or equal to the reference value (YES in step S141), the open-circuit voltage estimation unit 104 reads and acquires the previous voltage measurement values from the measurement result information 300 for the most recent predetermined number (for example, 10) (step S143), and proceeds to step S111. Here, if the measurement values cannot be acquired for the most recent predetermined number, it proceeds to step S127, and the OCV estimation process may not be performed and the previous OCV may be maintained.

[0080] On the other hand, when the voltage change amount ΔV is not less than or equal to the reference value (NO in step S141), the open-circuit voltage estimation unit 104 maintains the OCV (step S127) and proceeds to step S111.

[0081] Then, in step S111, the open-circuit voltage estimation unit 104 estimates the OCV using the voltage measurement value.

[0082] As described above, in the battery management device 100 of the present embodiment, when the voltage change amount ΔV becomes less than or equal to the reference value, the open-circuit voltage estimation unit 104 estimates the OCV using the previous voltage measurement values. That is, when the voltage change amount ΔV becomes small, the voltage drop rate becomes slow, and the OCV can be estimated using the measurement values when it is stable.

[0083] Thus, according to the battery management device 100 of the present embodiment, while achieving the same effects as those of the above embodiment, further, since the OCV is estimated using the measurement value when the voltage is relatively stable within the storage period, the estimation accuracy of the OCV can be improved, and thus, the estimation accuracy of the SOC can be improved.

[0084] (Fifth Embodiment) FIG. 10 is a diagram showing an overview of the battery management device 100 according to the embodiment. In the second embodiment, when the storage period is shorter than the predetermined time, the previous OCV was maintained. In this embodiment, it is different from the second embodiment in that when the storage period of the battery is shorter than the predetermined time, it has a configuration for estimating the OCV from the current integration value. The battery management device 100 in FIG. 10 has a voltage measurement unit 102, an open circuit voltage estimation unit 104, and a state of charge estimation unit 106 similar to those in FIG. 1, and further has an acquisition unit 108. However, the configuration of this embodiment may be combined within a range that does not conflict with at least any one of the configurations of other embodiments.

[0085] The acquisition unit 108 acquires the integration result of the current value during the use of the battery 10. When the time from the end of use to the resumption of use of the battery 10 is equal to or less than the predetermined time, the open circuit voltage estimation unit 104 estimates the OCV at the end of use of the battery 10 using the integration result of the current value.

[0086] The integration result of the current value during the use of the battery 10 can be acquired from the BMS 20. The BMS 20 periodically acquires the current value from the current meter during the use of the battery 10, that is, from after the ignition key of the vehicle 5 is turned on until the ignition key is turned off, performs an integration process, and may store it in the memory 1030 or the storage device 1040. Alternatively, the information processing device 200 may acquire it from the BMS 20 and store it in the storage device 220.

[0087] <Operation Example> FIG. 11 is a flowchart showing a main part of an operation example of the battery management device 100 according to the embodiment. The flow of this figure is executed instead of step S111 after the determination in step S125 of the flow of Figure 7 when the storage period is shorter than a predetermined time (YES in step S125). However, in the case of a configuration that does not include step S125 in Figure 7, the flow of this figure is executed before step S111 after the determination in step S121 when it is determined that it is not saturated (NO in step S121). The open circuit voltage estimation unit 104 estimates the OCV using the integration result of the current value during use of the battery 10 acquired by the acquisition unit 108 (step S151). Then, it proceeds to step S113, and the state of charge estimation unit 106 estimates the SOC.

[0088] As described above, in the battery management device 100 of the present embodiment, the acquisition unit 108 acquires the integration result of the current value during use of the battery 10. When the time from the end of use to the resumption of use of the battery 10 is equal to or less than a predetermined time, the open circuit voltage estimation unit 104 estimates the OCV at the end of use of the battery 10 using the integration result of the current value. That is, even when the storage period is short and polarization has not started, instead of maintaining the previous OCV, the OCV at the end of use of the battery 10 is estimated using the integration result of the current value during use of the battery 10 and can be used for the estimation of the SOC.

[0089] Thus, according to the battery management device 100 of the present embodiment, the same effects as those of the above embodiment can be achieved, and furthermore, the estimation accuracy of the OCV can be improved, and thus the estimation accuracy of the SOC can be improved.

[0090] As described above, the embodiments of the present invention have been described with reference to the drawings, but these are examples of the present invention, and various configurations other than the above can also be adopted. As described above, the present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. In addition, when acquiring and using information regarding the user in the present invention, it shall be done legally.

[0091] Examples of reference configurations will be appended below. 1. After the battery has been used up, voltage measuring means for repeatedly measuring the voltage of the battery between the time until the battery is used again, and open circuit voltage estimating means for estimating an open circuit voltage using the transition of the change in the measured voltage, and state of charge estimating means for estimating a state of charge (SOC) indicating the state of charge of the battery or a change amount (ΔSOC) of the SOC using the estimated open circuit voltage, a battery management device. 2. In the battery management device according to 1., when the inflection point of the voltage is detected, the open circuit voltage estimating means estimates the open circuit voltage using the measured value of the voltage after the inflection point, a battery management device. 3. In the battery management device according to 1. or 2., when the change amount of the voltage becomes equal to or less than a reference value, the open circuit voltage estimating means estimates the open circuit voltage using the measured value of the voltage before that, a battery management device. 4. In the battery management device according to any one of 1. to 3., further comprising acquisition means for acquiring an integrated result of the current value during use of the battery, and when the time from the end of use of the battery to the resumption of use is equal to or less than a predetermined time, the open circuit voltage estimating means estimates the open circuit voltage at the end of use of the battery using the integrated result of the current value, a battery management device. 5. In the battery management device according to any one of 1. to 4., the voltage measuring means gradually widens the measurement interval of the voltage, a battery management device.

[0092] 6. One or more computers after the battery has been used up, repeatedly measure the voltage of the battery between the time until the battery is used again, and estimate an open circuit voltage using the transition of the change in the measured voltage, and A battery management method for estimating the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open circuit voltage. 7. In the battery management method according to 6., When one or more computers detect the inflection point of the voltage, estimate the open circuit voltage using the measured value of the voltage after the inflection point, a battery management method. 8. In the battery management method according to 6. or 7., When one or more computers When the change amount of the voltage becomes equal to or less than a reference value, estimate the open circuit voltage using the measured value of the voltage before that, a battery management method. 9. In the battery management method according to any one of 6. to 8., When one or more computers obtain the integrated result of the current value during use of the battery, When the time from the end of use of the battery to the restart of use is equal to or less than a predetermined time, estimate the open circuit voltage at the end of use of the battery using the integrated result of the current value, a battery management method. 10. In the battery management method according to any one of 6. to 9., When one or more computers gradually widen the measurement interval of the voltage when measuring the voltage, a battery management method.

[0093] 11. A program for causing a computer to repeatedly measure the voltage of the battery between the end of use of the battery and the restart of use of the battery, estimate the open circuit voltage using the transition of the change in the measured voltage, estimate the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open circuit voltage. 12. In the program according to 11., In the procedure for estimating the open-circuit voltage, when an inflection point of the voltage is detected, the open-circuit voltage is estimated using the measured values of the voltage after the inflection point. A program. 13. In the program according to 11. or 12., In the procedure for estimating the open-circuit voltage, when the amount of change in the voltage becomes equal to or less than a reference value, the open-circuit voltage is estimated using the measured values of the voltage before that. A program. 14. In the program according to any one of 11. to 13., A procedure for obtaining an integrated result of the current value during use of the battery is executed by a computer. When the time from the end of use of the battery to the resumption of use is equal to or less than a predetermined time, in the procedure for estimating the open-circuit voltage, the open-circuit voltage at the end of use of the battery is estimated using the integrated result of the current value. A program. 15. In the program according to any one of 11. to 14., In the procedure for measuring the voltage, the measurement interval of the voltage is gradually widened. A program.

Explanation of symbols

[0094] 1 Battery management system 3 Communication network 5 Vehicle 10 Battery 20 BMS 30 Inflection point 32 Range 100 Battery management device 102 Voltage measurement unit 104 Open-circuit voltage estimation unit 106 State of charge estimation unit 108 Acquisition unit 200 Information processing device 220 Storage device 300 Measurement result information 1000 Computer 1010 Bus 1020 Processor 1030 Memory 1040 Storage device 1050 Input / output interface 1060 Network interface

Claims

1. Voltage measurement means for repeatedly measuring the voltage of the battery at a predetermined measurement interval throughout the period from the end of use of the battery to the resumption of use of the battery; Open-circuit voltage estimation means for estimating the open-circuit voltage using the transition of the measured change in the voltage when the use of the battery is resumed; State-of-charge (SOC) estimation means for estimating the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open-circuit voltage, comprising: The open-circuit voltage estimation means estimates the open-circuit voltage using the measured value of the voltage after the inflection point when the inflection point of the voltage is detected. A battery management device.

2. Voltage measurement means for repeatedly measuring the voltage of the battery at a predetermined measurement interval throughout the period from the end of use of the battery to the resumption of use of the battery; Open-circuit voltage estimation means for estimating the open-circuit voltage using the transition of the measured change in the voltage when the use of the battery is resumed; State-of-charge (SOC) estimation means for estimating the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open-circuit voltage; Acquisition means for acquiring the integrated result of the current value during use of the battery, comprising: When the time from the end of use of the battery to the resumption of use is equal to or less than a predetermined time, the open-circuit voltage estimation means estimates the open-circuit voltage at the end of use of the battery using the integrated result of the current value. A battery management device.

3. Voltage measurement means for repeatedly measuring the voltage of the battery after the end of use of the battery and before the resumption of use of the battery; Open-circuit voltage estimation means for estimating the open-circuit voltage using the transition of the measured change in the voltage; State-of-charge (SOC) estimation means for estimating the state of charge (SOC) indicating the state of charge of the battery or the change amount (ΔSOC) of the SOC using the estimated open-circuit voltage, comprising: The voltage measurement means stores the measured value of the voltage of the battery in a storage device; The open-circuit voltage estimation means reads out the measured values of the voltage before the time when the change amount of the voltage stored in the storage device becomes equal to or less than a reference value from the storage device for a predetermined number of the most recent ones and estimates the open-circuit voltage; The open-circuit voltage estimation means does not estimate the open-circuit voltage when the change amount of the voltage becomes equal to or less than a predetermined value. The state-of-charge estimation means is a battery management device that estimates the SOC or the change amount of the SOC by using the measured value of the voltage as the open-circuit voltage.

4. In the battery management device according to claim 3, when the open-circuit voltage estimation means cannot obtain the measured value of the voltage for the predetermined number of times from the storage device, the open-circuit voltage is not estimated. The state-of-charge estimation means is a battery management device that estimates the SOC or the change amount of the SOC by using the open-circuit voltage estimated by the open-circuit voltage estimation means last time.

5. In the battery management device according to claim 3, when the inflection point of the voltage is detected, the open-circuit voltage estimation means estimates the open-circuit voltage by using the measured value of the voltage after the inflection point.

6. In the battery management device according to claim 3, further comprising acquisition means for acquiring the integrated result of the current value during use of the battery. When the time from the end of use of the battery to the resumption of use is equal to or less than a predetermined time, the open-circuit voltage estimation means estimates the open-circuit voltage at the end of use of the battery by using the integrated result of the current value.

7. In the battery management device according to claim 1 or 2, the voltage measurement means gradually widens the predetermined measurement interval of the voltage.

8. One or more computers repeatedly measure the voltage of the battery at a predetermined measurement interval throughout the period from the end of use of the battery to the resumption of use of the battery. When the use of the battery is resumed, the open-circuit voltage is estimated by using the transition of the measured change in the voltage. The SOC (State Of Charge) indicating the state of charge of the battery or the change amount (△SOC) of the SOC is estimated by using the estimated open-circuit voltage. When estimating the open-circuit voltage, if an inflection point of the voltage is detected, the open-circuit voltage is estimated by using the measured value of the voltage after the inflection point.

9. One or more computers repeatedly measure the voltage of the battery during the period from the end of use of the battery to the resumption of use of the battery, and store the measured value of the voltage of the battery in a storage device. The open-circuit voltage is estimated by using the transition of the measured change in the voltage. The SOC (State Of Charge) indicating the state of charge of the battery or the change amount (△SOC) of the SOC is estimated by using the estimated open-circuit voltage. When estimating the open-circuit voltage, When the amount of change in the voltage stored in the memory device is equal to or less than a reference value, read the measured values of the voltage from the memory device for the most recent predetermined number of times before that point in time, and estimate the open-circuit voltage. When the amount of change in the voltage becomes equal to or less than a predetermined value, do not estimate the open-circuit voltage. A battery management method for estimating the state of charge (SOC) or the change amount of the SOC of the battery by using the measured value of the voltage as the open-circuit voltage.

10. On a computer, Repeatedly measure the voltage of the battery at a predetermined measurement interval throughout the period from after the end of use of the battery to the resumption of use of the battery. When the use of the battery is resumed, estimate the open-circuit voltage by using the transition of the measured change in the voltage. Execute procedures for estimating the state of charge (SOC) indicating the charge state of the battery or the change amount (ΔSOC) of the SOC by using the estimated open-circuit voltage. In the procedure for estimating the open-circuit voltage, when an inflection point of the voltage is detected, estimate the open-circuit voltage by using the measured values of the voltage after the inflection point. A program.

11. On a computer, After the end of use of the battery and before the resumption of use of the battery, repeatedly measure the voltage of the battery. Estimate the open-circuit voltage by using the transition of the measured change in the voltage. Execute procedures for estimating the state of charge (SOC) indicating the charge state of the battery or the change amount (ΔSOC) of the SOC by using the estimated open-circuit voltage. In the procedure for measuring the voltage, store the measured value of the voltage of the battery in a memory device. In the procedure for estimating the open-circuit voltage, When the amount of change in the voltage stored in the memory device is equal to or less than a reference value, read the measured values of the voltage from the memory device for the most recent predetermined number of times before that point in time, and estimate the open-circuit voltage. When the amount of change in the voltage becomes equal to or less than a predetermined value, do not estimate the open-circuit voltage. In the procedure for estimating the SOC or the change amount of the SOC, estimate the SOC or the change amount of the SOC by using the measured value of the voltage as the open-circuit voltage. A program.

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