Battery control system, power supply and demand system, battery control method, and battery control program

Abstract

Provided are a battery control system, a power supply and demand system, a battery control method, and a battery control program that even out variations between storage batteries of a battery system. A battery control system (10) applied to a battery system provided with a plurality of storage batteries comprises an apportionment adjustment rate setting unit (40) that acquires deterioration evaluation information, in which identification information and an SOH of each storage battery are associated with one another, from a storage unit (60) storing the deterioration evaluation information, and that uses the SOH of each of the plurality of storage batteries to set an apportionment adjustment rate, and a power command setting unit (50) that uses the apportionment adjustment rate to set an individual power command for each storage battery, wherein a target SOH is calculated by using the SOH of each storage battery constituting the battery system, and the apportionment adjustment rate is set for each storage battery such that the SOH of each storage battery approaches the target SOH.

Description

Battery control system, power supply and demand system, battery control method, and battery control program

[0001] The present disclosure relates to a battery control system, a power supply and demand system, a battery control method, and a battery control program.

[0002] In order to grasp the state of a storage battery, there is known a technique for measuring SOC (State of Charge, charging rate) and SOH (State of Health, degradation state, degradation evaluation value). For example, Patent Literature 1 discloses a storage battery state of charge calculation method that obtains a linear approximation of the current-voltage characteristics of a storage battery from the storage battery current and storage battery voltage, and estimates the state of charge and / or degradation state of the storage battery using the slope and intercept of the equation.

[0003] Japanese Patent Application Laid-Open No. 2005-345135

[0004] However, although the invention of Patent Document 1 estimates battery characteristics (storage battery performance level, SOH) and determines the lifespan of the storage battery, it does not consider the operation of a battery system when there is variation in the battery characteristics of multiple storage batteries. When there is variation in the battery characteristics of multiple storage batteries included in a battery system, it is difficult to extend the lifespan of the entire battery system.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a battery control system, a power supply and demand system, a battery control method, and a battery control program that can even out variations in the storage batteries of a battery system.

[0006] In order to solve the above problems, the battery control system, power supply and demand system, battery control method, and battery control program of the present disclosure employ the following means: The battery control system of the present disclosure is a battery control system applied to a battery system including a plurality of storage batteries, and includes: a sharing adjustment rate setting unit that acquires deterioration assessment information, in which identification information of the storage batteries is associated with an SOH, from a storage unit that stores the deterioration assessment information, and sets a sharing adjustment rate using the SOH of the plurality of storage batteries; and a power command setting unit that sets an individual power command for each of the storage batteries using the sharing adjustment rate, and calculates a target SOH using the SOH of each of the storage batteries that constitute the battery system, and sets the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

[0007] The power supply and demand system of the present disclosure includes a battery system including a plurality of storage batteries and the battery control system described above.

[0008] The battery control method disclosed herein is a battery control method applied to a battery system having a plurality of storage batteries, and includes a sharing adjustment rate setting process for acquiring deterioration assessment information, in which the deterioration assessment information is associated with the identification information and SOH of the storage batteries, from a memory unit in which the deterioration assessment information is stored, and setting a sharing adjustment rate using the SOH of the plurality of storage batteries, and a power command setting process for setting individual power commands for each of the storage batteries using the sharing adjustment rate, in which a computer executes the process of calculating a target SOH using the SOH of each of the storage batteries that constitute the battery system, and setting the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

[0009] The battery control program of the present disclosure causes a computer to execute the above-described battery control method.

[0010] According to the present disclosure, the sharing adjustment rate of each storage battery is set based on the SOH, which is a deterioration evaluation value, so that power sharing can be appropriately performed to extend the life of the entire battery system, taking into account the variation in SOH between each storage battery.

[0011] 6 is a diagram illustrating a schematic configuration of an electric power supply and demand system according to some embodiments of the present disclosure. FIG. 7 is a diagram illustrating an example of a hardware configuration of a battery control system according to some embodiments of the present disclosure. FIG. 8 is a functional configuration diagram illustrating an example of functions provided in a battery control system according to some embodiments of the present disclosure. FIG. 9 is a functional configuration diagram illustrating an example of functions provided in a degradation state evaluation unit according to some embodiments of the present disclosure. FIG. 10 is a diagram illustrating a case where the sharing rate of a storage battery according to some embodiments of the present disclosure is defined in a range from 0 to 1. FIG. 11 is a diagram illustrating an example of a sharing adjustment rate of a storage battery. As shown in FIG. 6, examples of individual power commands when 0.8 and 1.2 are set as the sharing adjustment rate are compared. As shown in FIG. 6, examples of charge and discharge currents when 0.8 and 1.2 are set as the sharing adjustment rate are compared. As shown in FIG. 6, examples of SOCs when 0.8 and 1.2 are set as the sharing adjustment rate are compared. FIG. 11 is a flowchart illustrating an example of a procedure for a degradation state evaluation process executed by a battery control system according to some embodiments of the present disclosure. FIG. 12 is a flowchart illustrating an example of a procedure for an individual power command setting process executed by a battery control system according to some embodiments of the present disclosure. FIG. 13 is a diagram for explaining the effects of a battery control system according to some embodiments of the present disclosure. Fig. 1 is a diagram showing a schematic configuration of a power supply and demand system according to some embodiments of the present disclosure. Fig. 2 is a functional configuration diagram showing an example of functions of a battery control system according to some embodiments of the present disclosure. Fig. 3 is a diagram showing a relationship between an individual power command and a bus voltage of a DC link according to some embodiments of the present disclosure. Fig. 4 is a diagram showing an example of a relationship between the slope of storage batteries with different SOH and individual power commands.

[0012] [First embodiment] Hereinafter, a power supply and demand system, a battery control system, a battery control method, and a program according to a first embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a diagram showing a schematic configuration of a power supply and demand system according to some embodiments of the present disclosure. As shown in Fig. 1, a power supply and demand system 100 includes a battery system (ESS: Energy Storage System) 1 and a battery control system 10.

[0013] The battery system 1 is connected to a power grid 2 via a substation 3, and supplies and demands power to and from the power grid 2. The substation 3 and the battery system 1 are connected by an AC link 4. The battery system 1 includes multiple storage batteries 5 (5a to 5d). While FIG. 1 illustrates an example in which four storage batteries 5 are included, the number of storage batteries 5 is not limited. Hereinafter, when it is necessary to distinguish between the storage batteries 5a, 5b, etc., they will be referred to as storage batteries 5a, 5b, and when there is no need to distinguish between them, they will be simply referred to as storage batteries 5. The same applies to other configurations.

[0014] Each storage battery 5 is chargeable and dischargeable, and is configured, for example, as a battery string in which a plurality of unit batteries (cells) are connected in series. Alternatively, a configuration in which a plurality of battery strings are connected in parallel may be used. Each storage battery 5 may include a measurement unit (not shown) that measures various data (battery information) such as voltage value, current value, and temperature, and a battery management unit (BMU: Battery Management Unit) (not shown) that monitors the state of the storage battery 5 based on this measurement data. The configuration of the storage battery 5 may be any known technology and is not particularly limited.

[0015] Each storage battery 5 is connected to the AC link 4 via a power converter 7 (7a to 7d). The power converter 7 is, for example, an AC / DC converter. The power converter 7 controls the charging and discharging of the storage batteries 5 by operating based on, for example, individual power commands provided from the battery control system 10. Specifically, the power converter 7a controls the charging and discharging of the storage battery 5a, the power converter 7b controls the charging and discharging of the storage battery 5b, the power converter 7c controls the charging and discharging of the storage battery 5c, and the power converter 7d controls the charging and discharging of the storage battery 5d. During charging, the power converter 7 converts AC power from the power grid 2 into DC power and outputs it to the storage batteries 5. During discharging, the power converter 7 converts DC power from the storage batteries 5 into AC power and supplies it to the power grid 2.

[0016] The battery control system 10 is a control system that controls the battery system 1. The battery control system 10 is connected to the battery system 1, for example, via a communication network, and is configured to be able to exchange information. The battery control system 10 may be a cloud server or a local system installed at the installation location of the battery system 1. The battery control system 10 is connected to a grid monitoring system 6 via the communication network. The grid monitoring system 6 is, for example, a central power supply command center of a power company or a higher-level energy management system (EMS). The grid monitoring system 6 determines a system power request to be made to the battery system 1 and transmits the system power request to the battery control system 10.

[0017] Next, a battery control system 10 according to the present embodiment will be described. FIG. 2 is a diagram showing an example of a hardware configuration of a battery control system according to some embodiments of the present disclosure. As shown in FIG. 2, the battery control system 10 is a computer and includes, for example, a CPU (Central Processing Unit: processor) 11, a main memory 12, a secondary storage 13, a communication interface 14, and the like. The battery control system 10 may also include an input device 15 that accepts input from a user, a display 16, and the like. These components are connected via a bus 18.

[0018] The main storage device 12 is composed of writable memory such as cache memory, RAM (Random Access Memory), etc., and is used as a work area for reading execution programs of the CPU 11 and writing processing data by the execution programs. The secondary storage device 13 is a non-transitory computer-readable storage medium. Examples of the secondary storage device 13 include magnetic disks such as HDDs (Hard Disk Drives), magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories such as SSDs (Solid State Drives).

[0019] 3 is a functional configuration diagram showing an example of functions of a battery control system according to some embodiments of the present disclosure. The battery control system 10 evaluates the state of degradation of each storage battery 5 while the battery system 1 is connected to the power grid 2, and controls the charging and discharging of each storage battery 5 using the evaluation results of the state of degradation. Specifically, as shown in FIG. 3 , the battery control system 10 includes a degradation state evaluation unit 20, a data management unit 30, a sharing adjustment rate setting unit 40, a power command setting unit 50, and a storage unit 60.

[0020] A series of processes for realizing the various functions described below is stored in the secondary storage device 13 (see FIG. 2) in the form of a program (e.g., a battery control program), for example, and the CPU 11 reads this program into the main storage device 12 and executes information processing and arithmetic operations to realize the various functions. The program may be pre-installed in the secondary storage device 13, provided in a state stored in another computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0021] The degradation state evaluation unit 20 performs degradation state evaluation to evaluate the degradation state of the storage battery 5. The degradation state evaluation is performed while the storage battery 5 is connected to the power grid 2. The degradation state evaluation is started when a preset start condition is satisfied. Examples of the start condition include when a predetermined period has elapsed since the previous degradation state evaluation, when the cumulative operating time since the previous degradation state evaluation reaches a predetermined time, or when a command to start the degradation state evaluation is input by the user. The start condition may be set as a combination of these. The cycle of the degradation state evaluation may be set to be shorter as the degradation evaluation value decreases.

[0022] FIG. 4 is a functional configuration diagram illustrating an example of functions included in the degradation state evaluation unit in some embodiments of the present disclosure. As shown in FIG. 4 , the degradation state evaluation unit 20 includes, for example, a selection unit 21, a measurement execution unit 22, a recovery control unit 23, and an evaluation value calculation unit 24. The selection unit 21 sequentially selects storage batteries 5 to be evaluated during degradation state evaluation. Specifically, during degradation state evaluation, the selection unit 21 selects one or more storage batteries 5 to be evaluated according to a predetermined algorithm. Then, when the measurement execution unit 22 (described later) finishes evaluating the degradation state of the storage batteries 5 selected as the evaluation targets, the selection unit 21 selects one or more storage batteries 5 to be evaluated next as the evaluation targets. The selection unit 21 repeats the selection until all storage batteries 5a to 5d included in the battery system 1 have been selected as evaluation targets. For convenience of explanation, this embodiment will be described with an example in which the selection is performed sequentially in the order of storage batteries 5a, 5b, 5c, and 5d.

[0023] The measurement execution unit 22 controls the charging and discharging of the storage battery 5 to be evaluated in accordance with a preset charging and discharging pattern, and acquires the voltage value or current value at this time. Specifically, the measurement execution unit 22 issues a charging and discharging command in accordance with the predetermined charging and discharging pattern to the power conversion device 7 corresponding to the storage battery 5 to be evaluated. As a result, the power conversion device 7 is driven in accordance with the charging and discharging pattern, thereby realizing charging and discharging in accordance with the charging and discharging pattern.

[0024] After the measurement execution unit 22 finishes measuring, in other words, after the charge / discharge control based on the predetermined charge / discharge pattern is completed, the recovery control unit 23 controls the charge / discharge of the storage battery under evaluation (e.g., 5a) so as to bring the state of charge of the storage battery under evaluation closer to the state of charge of the operational storage batteries (e.g., 5b-5d). Then, when the state of charge of the storage battery under evaluation (e.g., 5a) and the state of charge of the operational storage batteries (e.g., 5b-5d) satisfy predetermined conditions, the recovery control unit 23 recovers the storage battery under evaluation as an operational storage battery. For example, the recovery control unit 23 may recover the storage battery under evaluation as an operational storage battery when the difference between the average cell voltage of the storage battery under evaluation and the average value of the average cell voltages of the operational storage batteries falls within a predetermined range. Instead of the average cell voltage, the charge rate may be used.

[0025] The evaluation value calculation unit 24 calculates a degradation evaluation value that evaluates the degradation state of the storage battery 5 to be evaluated based on the current value or voltage value when charge / discharge control is performed by the measurement execution unit 22. For example, the evaluation value calculation unit 24 receives battery information (current value, voltage value, temperature, etc.) from the storage battery 5 to be evaluated, and calculates a degradation evaluation value based on the received battery information.

[0026] The degradation evaluation value is, for example, an evaluation value that indicates a decrease in the current full charge capacity of the storage battery 5 relative to the initial full charge capacity, and one example is the SOH (State of Health). The evaluation value calculation unit 24 calculates the latest full charge capacity (Ah) by, for example, integrating the current value when the storage battery 5 to be evaluated is changed from a fully charged state to a lower charge limit state, or from the lower charge limit state to a fully charged state. The evaluation value calculation unit 24 then calculates the SOH by dividing the latest full charge capacity by the full charge capacity at the start (initial) of operation of the battery system 1. The method for evaluating the degradation state of the battery is not limited to the above example. For example, any known technology for evaluating the degradation state of a battery can be appropriately adopted.

[0027] After calculating the degradation evaluation values ​​for all of the storage batteries 5a to 5d, the evaluation value calculation unit 24 outputs degradation evaluation information that associates the identification information of each storage battery with the degradation evaluation value to the data management unit (see FIG. 3). The degradation evaluation information may also include time information, battery information of each storage battery 5a to 5d acquired by the measurement execution unit 22, and the like.

[0028] The data management unit 30 (see FIG. 3 ) stores, for example, the degradation assessment information acquired from the degradation state assessment unit 20 in the storage unit 60. The data management unit 30 stores in the storage unit 60 the sharing adjustment rates of the storage batteries 5 a to 5 d calculated by the sharing adjustment rate setting unit 40 (described later) and the like.

[0029] The sharing adjustment rate setting unit 40 sets a sharing adjustment rate for each of the storage batteries 5a to 5d based on the deterioration evaluation value (SOH) of each of the storage batteries 5a to 5d stored in the memory unit 60. For example, the sharing adjustment rate setting unit 40 calculates a target deterioration evaluation value using the deterioration evaluation values ​​of the storage batteries 5a to 5d that constitute the battery system 1, and sets a sharing adjustment rate for each storage battery that brings the deterioration evaluation value of each of the storage batteries 5a to 5d closer to this target deterioration evaluation value. The target deterioration evaluation value is, for example, the average value of the deterioration evaluation values ​​of the storage batteries 5a to 5d.

[0030] As a result, a larger sharing adjustment rate is set for a storage battery 5 with a high degradation evaluation value (for example, a high SOH) than for a storage battery 5 with a low degradation evaluation value. A storage battery 5 with a high sharing adjustment rate is assigned a larger portion of the required power relative to the system required power than a storage battery 5 with a low sharing adjustment rate. That is, during charging, a storage battery 5 with a high sharing adjustment rate charges more power than a storage battery 5 with a low sharing adjustment rate, and during discharging, a storage battery 5 with a high sharing adjustment rate discharges more power than a storage battery 5 with a low sharing adjustment rate.

[0031] For example, the sharing adjustment rate setting unit 40 calculates the sharing adjustment rate α(i) using a target degradation evaluation value SOHave, which is the average value of the SOH of the storage batteries 5a to 5d, and each deviation ΔSOH(i) between the target degradation evaluation value SOHave and the SOH(i) of each storage battery 5. As an example, the sharing adjustment rate α(i) is calculated using the following equation (1).

[0032] Sharing adjustment rate α(i) = {1+K(ΔSOH(i) / SOHave)} (1)

[0033] In the above formula (1), i indicates the identification information of the storage batteries 5a to 5d (for example, i = 1 to 4), and for example, the sharing adjustment rate α(1) of the storage battery 5a is expressed by the following formula.

[0034] Sharing adjustment rate α(1) = {1+K(ΔSOH(1) / SOHave)}

[0035] In the above formula (1), K is an adjustment gain, and the larger this adjustment gain K is, the shorter the time it takes for the variation in the degradation evaluation value to fall within a predetermined range. The adjustment gain K is a value equal to or greater than zero. The adjustment gain K is a value that can be changed as appropriate.

[0036] When the adjustment gain K is set to zero, the power sharing adjustment rate of each of the storage batteries 5a to 5d becomes 1, and in this case, there is no increase or decrease in the power sharing according to SOH(i). In other words, the system required power is allocated equally to each storage battery.

[0037] In the above formula (1), if the SOH(i) of each storage battery 5 is equal to the target degradation evaluation value SOHave, the deviation ΔSOH(i) between the target degradation evaluation value SOHave and the SOH(i) of each storage battery 5 will be zero, and the share adjustment rate of each storage battery 5a to 5d will be 1. In this case, there will be no increase or decrease in the power share according to SOH(i). In other words, the system required power will be allocated equally to each storage battery.

[0038] When the adjustment gain K is set to 1, the sharing adjustment rate α(i) of each of the storage batteries 5a to 5d is expressed by the following equation.

[0039] Sharing adjustment rate α(i) = {1+(ΔSOH(i) / SOHave)}

[0040] If the target deterioration evaluation value SOHave is 50(%) and the SOH(1) for i=1 is also 50(%), then ΔSOH(1) = 50 - 50 = 0(%), and therefore the sharing adjustment rate α(1) is expressed by the following formula.

[0041] Sharing adjustment rate α(1)={1+(ΔSOH(1) / SOHave)}=1

[0042] In this case, if SOHave is 50(%) and SOH(2) for i=2 is 100(%) (twice that for i=1), then ΔSOH(2) = 100-50 = 50(%), and therefore the sharing adjustment rate α(2) is expressed by the following formula.

[0043] Sharing adjustment rate α(2)={1+(ΔSOH(2) / SOHave)}=2

[0044] That is, for a storage battery 5 with twice the SOH of the reference storage battery 5, the sharing adjustment rate α is doubled, and the charge / discharge amount during charging / discharging is also doubled. When selected in this way, it is possible to operate each storage battery so that the behavior of the SOC (charging rate) is approximately the same.

[0045] For example, when a predetermined calculation start condition is satisfied, the sharing adjustment rate setting unit 40 calculates the sharing adjustment rate α(i) and updates each sharing adjustment rate α(i) in the storage unit 60. Here, the predetermined calculation start condition may be, for example, when the degradation state evaluation unit 20 performs a degradation state evaluation, thereby calculating degradation evaluation values ​​for all of the storage batteries 5 a to 5 d, and degradation evaluation information including the degradation evaluation values ​​for these storage batteries 5 a to 5 d is stored in the storage unit 60. The sharing adjustment rate setting unit 40 may update the sharing adjustment rate α(i) when the operation mode of the battery system 1 changes, for example, when a storage battery 5 is suspended.

[0046] After calculating the sharing adjustment rate for each of the storage batteries 5a to 5d, the sharing adjustment rate setting unit 40 outputs sharing adjustment rate information that associates the identification information of each storage battery with the sharing adjustment rate to the data management unit 30 (see FIG. 3). The sharing adjustment rate information may also include time information and the like.

[0047] In equation (1), the sharing adjustment rate is defined as "1" when the number of storage batteries 5 is one. For example, when the number of storage batteries 5 is four, the total number of sharing adjustment rates is four. On the other hand, when the sharing adjustment rate per storage battery 5 is defined as a value between 0 and 1, it is calculated as follows. FIG. 5 is a diagram showing a case where the sharing adjustment rate of a storage battery according to some embodiments of the present disclosure is defined in the range from 0 to 1. As shown in FIG. 5 , the sharing adjustment rate X(i) (i is an integer greater than or equal to 1, i = 1, ..., N) of a storage battery 5 is calculated from the total number N of storage batteries 5 (N is an integer greater than or equal to 2) and the SOH value of each storage battery 5. The sharing adjustment rate X(i) of a storage battery 5 is adjusted by an adjustment gain K.

[0048] When K is zero, each share adjustment rate X(i) is 1 / N, which is an equal value. Therefore, there is no increase or decrease in power share, and the system required power is allocated equally to each storage battery.

[0049] When K is 1, the sharing adjustment rate X(i) is a power sharing rate that matches the SOH capacity of each storage battery 5, and the amplitude (variation range) of the SOC of each storage battery 5 becomes uniform.

[0050] When K exceeds 1, the sharing adjustment rate X(i) is set so that the larger the SOH capacity of the storage battery 5, the more power is shared. A large load is applied to the storage battery 5 with a large SOH capacity, while a smaller load is applied to the storage battery 5 with a small SOH capacity. As a result, the amplitude (range of change) of the SOC of each storage battery 5 is not uniform, resulting in an SOC imbalance.

[0051] The power command setting unit 50 calculates an individual power command Pdiv(i) for each operational storage battery using the sharing adjustment rate α(i) corresponding to each storage battery 5a to 5d and the system required power Pall obtained from the grid monitoring system 6. Here, the operational storage battery is an operable storage battery 5, in other words, a storage battery 5 capable of charge / discharge control in response to the system required power Pall. In other words, the storage battery 5 for which degradation is evaluated by the above-described degradation state evaluation unit 20 is excluded from the operational storage batteries.

[0052] The power command setting unit 50 acquires the sharing adjustment rate α(i) of each operating storage battery stored in the memory unit 60, and calculates the individual power command for each operating storage battery by using the acquired sharing adjustment rate α(i) and the system required power Pall in the following equation (2).

[0053] Pdiv(i)=Pall×(1 / N)×α(i) (2)

[0054] In the above formula (2), N represents the number of operational batteries. For example, when the degradation state evaluation unit 20 has not performed the degradation state evaluation, the batteries 5a to 5d may be operational batteries, and when the degradation state evaluation is being performed, the batteries 5 other than those being evaluated may be operational batteries.

[0055] As can be seen from equation (2), a larger individual power command is set for an operating battery with a high degradation evaluation value (high health) than for an operating battery with a low degradation evaluation value. After allocating an individual power command Pdiv(i) to each operating battery, the power command setting unit 50 transmits the individual power command Pdiv(i) to the power conversion device 7 corresponding to each operating battery. As a result, charge and discharge control according to the individual power command Pdiv is performed in each operating battery.

[0056] The sum of the sharing adjustment rates α(i) of the operating storage batteries is expressed by the following equation (3).

[0057] Σα(i)=Σ{1+K(ΔSOH(i) / SOHave)}=Σ1=N (3)

[0058] The sum of the individual power commands Pdiv(i) for each of the operating storage batteries is expressed by the following equation (4).

[0059] ΣPdiv(i)=ΣPall×(1 / N)×α(i)=Pall / N×Σα(i) (4)

[0060] Therefore, the sum of the individual power commands Pdiv(i) for each operating battery is expressed by the following equation (5) from equations (3) and (4).

[0061] ΣPdiv(i)=Pall / N×N=Pall (5)

[0062] Therefore, except in cases where charging and discharging according to the individual power command Pdiv(i) is not possible due to limitations in the power converter, the sum of the individual power commands Pdiv(i) for each operating storage battery is determined to match the system required power Pall.

[0063] For example, when the SOH(2) of battery 5b is higher than the SOH(1) of battery 5a, i.e., SOH(1)<SOH(2), and the sharing adjustment rate α(1) of battery 5a is set to 0.8 and the sharing adjustment rate α(2) of battery 5b is set to 1.2 as shown in FIG. 6, examples of the individual power commands, charge / discharge currents, and SOCs are shown in FIGS. 7 to 9, respectively. In FIGS. 7 to 9, the solid lines represent battery 5a and the dashed lines represent battery 5b. As shown in FIGS. 7 to 9, the individual power command of battery 5b is larger than that of battery 5a, and therefore the charge / discharge current of battery 5b is larger than that of battery 5a, and the amplitude of the SOC is also larger than that of battery 5a.

[0064] Next, the operation of the battery control system 10 according to this embodiment will be described. Fig. 10 is a flowchart showing an example of the procedure of a degradation state evaluation process executed by a battery control system according to some embodiments of the present disclosure. The degradation state evaluation process described below is started when a preset condition for starting degradation state evaluation is satisfied. For convenience of explanation, the following description will be given taking as an example a case where degradation state evaluation is performed on the storage batteries 5a, 5b, 5c, and 5d in that order.

[0065] First, the battery control system 10 selects a storage battery 5a to be evaluated for its deterioration state (SA1), controls the charging and discharging of the storage battery 5a to be evaluated according to a predetermined charging and discharging pattern, and obtains battery information such as the voltage value, current value, and temperature of the storage battery 5a at this time from the battery system 1 (SA2).

[0066] When the charge / discharge control of the storage battery 5a being evaluated is completed, a degradation evaluation value is calculated from the acquired battery information (SA3), and the identification information "#1" of the storage battery 5a being evaluated is associated with the degradation evaluation value and stored in internal memory (SA4). Next, a restoration process is performed (SA5). In the restoration process, the charge / discharge of the storage battery 5a being evaluated is controlled so that the charging rate of the storage battery 5a being evaluated approaches the charging rates of the operational batteries 5b to 5d. Then, when the charging rate of the storage battery 5a being evaluated satisfies a predetermined condition defined in relation to the charging rates of the operational batteries, the storage battery 5a being evaluated is restored as an operational battery.

[0067] Next, the system determines whether all of the storage batteries 5a to 5d have been selected as evaluation targets (SA6). In this case, because none of the storage batteries 5a to 5d have been selected (SA6: NO), the system returns to step SA1 and selects the unselected storage battery 5b as the evaluation target. Then, a degradation state evaluation is performed for the storage battery 5b. If the storage battery 5b has been selected as the evaluation target, the storage batteries 5a, 5c, and 5d are the operational storage batteries. The same process is performed for the storage batteries 5c and 5d. If it is determined in step SA6 that all of the storage batteries 5a to 5d have been selected as evaluation targets (SA6: YES), degradation evaluation information associating the identification information #1 to #4 of each storage battery 5a to 5d with its degradation evaluation value is output (SA7), and the process ends. This causes the degradation evaluation values ​​of each storage battery 5a to 5d to be stored in the storage unit 60.

[0068] In this way, when the deterioration evaluation value is updated and, for example, a condition for starting calculation of the sharing adjustment rate is satisfied, the battery control system 10 executes, for example, a sharing adjustment rate setting process. In the sharing adjustment rate setting process, a sharing adjustment rate is calculated based on the latest deterioration evaluation value of each storage battery. The calculated sharing adjustment rate is associated with the identification information of each storage battery 5a to 5d and stored in the memory unit 60. As a result, the latest sharing adjustment rate for each storage battery 5a to 5d is stored in the memory unit 60, and the sharing adjustment rate is updated.

[0069] Next, the individual power command setting process executed by the battery control system 10 will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the procedure of the individual power command setting process executed by the battery control system according to some embodiments of the present disclosure. This process starts when operation of the battery system 1 is started and ends when operation is completed.

[0070] First, the battery control system 10 obtains the sharing adjustment rate α(i) for each of the storage batteries 5a to 5d from the storage unit 60 (SB1). Next, it determines whether a degradation state evaluation is in progress (SB2). If a degradation state evaluation is in progress (SB2: YES), the system identifies operational batteries excluding the storage battery 5 being evaluated (SB3). For example, if the storage battery 5a is selected as the storage battery 5 being evaluated, the storage batteries 5b to 5d are identified as operational batteries. On the other hand, if a degradation state evaluation is not in progress (SB2: NO), the system identifies the storage batteries 5a to 5d as operational batteries.

[0071] Next, for each operating battery, an individual power command is set using the sharing adjustment rate α(i) (SB4), and each individual power command is sent to each operating battery (SB5). This enables charge / discharge control that reflects the degradation evaluation value (e.g., SOH(i)) of each operating battery. Next, it is determined whether or not control of the battery system 1 has ended (SB6). If not (SB6: NO), the process returns to step SB2 and repeats the subsequent steps. On the other hand, if control has ended (SB6: YES), the process ends.

[0072] As described above, the battery control system 10 according to this embodiment includes a degradation state evaluation unit 20 that sequentially selects storage batteries 5 to be evaluated for their degradation states, and calculates a degradation evaluation value relating to the degradation state of the storage batteries 5 to be evaluated using voltage values ​​or current values ​​when charging and discharging of the storage batteries 5 to be evaluated according to a preset charge and discharge pattern, and a data management unit 30 that associates identification information of the storage batteries 5 with the degradation evaluation values ​​and stores them in the storage unit 60. As a result, the degradation evaluation values ​​of the storage batteries 5a to 5d are stored in the storage unit 60, and the degradation evaluation values ​​in the storage unit 60 are updated each time a degradation state evaluation is performed.

[0073] Furthermore, according to this embodiment, the battery control system 10 includes a sharing adjustment rate setting unit 40 that sets a sharing adjustment rate α(i) using the deterioration evaluation values ​​of the multiple storage batteries 5a to 5d stored in the memory unit 60, and a power command setting unit 50 that sets an individual power command for each operational storage battery using the sharing adjustment rate α(i). This makes it possible to operate operational storage batteries 5 other than those being evaluated while evaluating their state of health. In this case, the operational storage batteries are controlled based on individual power commands set using the sharing adjustment rate α(i) calculated based on their respective deterioration evaluation values. This makes it possible to suppress variations in the deterioration evaluation values ​​(SOH) among the storage batteries 5, thereby extending the life of the battery system 1 as a whole.

[0074] FIG. 12 is a diagram illustrating the effects of a battery control system according to some embodiments of the present disclosure. FIG. 12 illustrates an example of battery life compared between when the battery control system 10 according to this embodiment is applied and when it is not applied. As shown in FIG. 12 , without control, the same individual power command is given to the storage batteries 5 regardless of their SOH, so that the storage batteries 5 with a low SOH in the initial state reach the end of their life first. On the other hand, when the battery control system 10 according to this embodiment is applied, more individual power commands are given to the storage batteries 5 with a high SOH, and relatively fewer individual power commands are given to the storage batteries 5 with a low SOH. This makes it possible to gradually reduce the variation in SOH among the storage batteries 5. This particularly extends the life of the storage batteries 5 with a low SOH in the initial state, thereby extending the life of the battery system 1 as a whole, as shown in FIG. 12 .

[0075] Second Embodiment Next, a power supply and demand system, a battery control system, a battery control method, and a program according to a second embodiment of the present disclosure will be described with reference to the drawings. In the power supply and demand system 100 according to the first embodiment described above, the power conversion device 7 is an AC / DC converter, and the battery system 1 is connected to the AC link 4 via this power conversion device 7. In contrast, in a power supply and demand system 100a according to this embodiment, as shown in FIG. 13 , the battery system 1a is connected to the DC link 8 via a power conversion device 7′ (7a′ to 7d′) that is a DC / DC converter. The DC link 8 and the substation 3 are connected via an AC / DC converter 9.

[0076] 14 is a functional configuration diagram showing an example of functions provided in a battery control system according to some embodiments of the present disclosure. As shown in FIG. 14, in this embodiment, the functions of the sharing adjustment rate setting unit 40a and the power command setting unit 50a are different from those of the first embodiment described above. Hereinafter, the same components as those in the first embodiment will be assigned the same reference numerals and their description will be omitted, and the different components will be mainly described.

[0077] When the battery system 1a is connected to the DC link 8, it is necessary to control the charging and discharging of the battery system 1 so that the bus voltage of the DC link 8 falls within a voltage range required by the power grid. For example, when the voltage of the DC link 8 rises due to the supply of power from the power grid 2, the battery system 1a is charged with power corresponding to the voltage rise, thereby suppressing the voltage rise of the DC link 8. Conversely, when the voltage of the DC link 8 drops due to the supply of power to the power grid 2, the battery system 1a is discharged with power corresponding to the voltage drop, thereby suppressing the voltage drop of the DC link 8.

[0078] FIG. 15 is a diagram illustrating the relationship between an individual power command and a bus voltage of a DC link according to some embodiments of the present disclosure. In FIG. 15 , the horizontal axis represents power, the vertical axis represents the differential voltage between the target voltage of the DC link 8 and the operating voltage of the DC link 8, and the relationship between the differential voltage and the individual power command is indicated by a solid line. In FIG. 15 , +Vm_max represents, for example, the maximum allowable voltage relative to the target voltage of the DC link 8, and −Vm_max represents, for example, the minimum allowable voltage relative to the target voltage of the DC link 8. In other words, Vm_max and −Vm_max represent the upper and lower limits, respectively, of the allowable voltage range relative to the target voltage of the DC link 8. Here, the allowable maximum voltage and the allowable minimum voltage are merely examples and are not limited thereto. In other words, they may be set appropriately depending on the operation of the battery system 1, etc. In FIG. 15 , −Pmax represents the upper limit power charge of the power conversion device 7′, and +Pmax represents the upper limit power discharge of the power conversion device 7′, as an example, but are not limited thereto. In other words, they may be set appropriately depending on the operation of the battery system 1, etc. From FIG. 15, the relationship between the individual power command Pdiv and the differential voltage Vp is expressed by the following equation (6).

[0079] Vp = -a x Pdiv (6) where a = Vmax / Pmax

[0080] When the above formula (6) is converted into a formula for deriving Pdiv, the following formula (7) is obtained: Pdiv=-Vp / a (7)

[0081] As shown in Fig. 15, when the current differential voltage Vp = +ΔV1, the individual power command Pdiv is P1 (charging), and when the current differential voltage Vp = -ΔV2, the individual power command Pdiv is P2 (discharging). From Fig. 15, it can be seen that the individual power command Pdiv is set to a larger value as the operating voltage of the DC link 8 deviates from the target voltage. It can also be seen that when the slope a is increased, the individual power command decreases, and when the slope a is decreased, the individual power command increases. Therefore, in this embodiment, the slope a is changed in accordance with the deterioration evaluation value, more specifically, the sharing adjustment rate α(i) calculated in the first embodiment, thereby performing charge / discharge control of each storage value in accordance with the deterioration evaluation value.

[0082] In this embodiment, the sharing adjustment rate setting unit 40a calculates the slope a(i) by using the sharing adjustment rate α(i) of each storage battery in the following equation (8).

[0083] a(i)=a×{1 / α(i)} (8)

[0084] In equation (5), a(i) is the slope of the storage battery 5 with identification information i, a is the default slope (a=Vmax / Pmax), and α(i) is the sharing adjustment rate of the storage battery 5 with identification information i, which are calculated using equation (2) above. As can be seen from equation (5), a slope that is smaller for an operating storage battery with a high degradation evaluation value (high health) than for an operating storage battery with a low degradation evaluation value is set.

[0085] After calculating the slope a(i) for each storage battery, the sharing adjustment rate setting unit 40a outputs slope information that associates the identification information of each storage battery with the slope to the data management unit 30. Time information and the like may be added to the slope information.

[0086] The power command setting unit 50a calculates an individual power command Pdiv(i) for each operating storage battery using the slope a(i) corresponding to each storage battery and the operating voltage (actually measured voltage) of the DC link 8. For the operating voltage of the DC link 8, for example, information notified from the battery system 1, more specifically, the power conversion device 7′, can be used. Specifically, the power command setting unit 50a acquires the slope a(i) for each storage battery stored in the storage unit 60, and calculates the individual power command Pdiv(i) for each storage battery by using the acquired sharing adjustment rate α(i) and the differential voltage Vp between the operating voltage of the DC link 8 and the target voltage in the following equation (9):

[0087] Pdiv(i)=-Vp / a(i) (9)

[0088] After allocating the individual power command Pdiv(i) to each operating battery, the power command setting unit 50a transmits the individual power command Pdiv(i) to the power conversion device 7′ corresponding to each operating battery. As a result, charge / discharge control according to the individual power command Pdiv(i) is performed in each operating battery.

[0089] For example, an example of the slope and individual power commands when the SOH(2) of storage battery 5b is higher than the SOH(1) of storage battery 5a is shown in comparison in Figure 16. As shown in Figure 16, the individual power commands Pc(2) and Pd(2) of storage battery 5b are larger than the individual power commands Pc(1) and Pd(1) of storage battery 5a, so the charge / discharge current of storage battery 5b is larger than that of storage battery 5a, and the amplitude of the SOC also becomes a larger value than that of storage battery 5a.

[0090] In this way, when the battery system 1 is connected to the DC link 8, it is possible to set an individual power command for each storage battery based on the SOH using the slope information.

[0091] Third Embodiment Next, a power supply and demand system, a battery control system, a battery control method, and a program according to a third embodiment of the present disclosure will be described with reference to the drawings. While the power supply and demand system 100 according to the second embodiment described above calculates the sharing adjustment rate based on the SOH, the power supply and demand system 100 according to this embodiment differs from the second embodiment described above in that it calculates the sharing adjustment rate by predicting the influence of ambient temperature, but is otherwise similar to the second embodiment. Here, differences from the second embodiment will be mainly described, and duplicated descriptions of parts that are the same as those in the second embodiment will be omitted. The same reference numerals will be used for parts that are the same as those in the second embodiment.

[0092] In calculating the sharing adjustment rate, the sharing adjustment rate setting unit 40 predicts SOH[i](t+Δt), which is the predicted value of SOH after Δt (SOH predicted value), based on the SOH[i](t) measured from the storage battery 5[i] at time t, the storage battery current I[i](t) and charging rate SOC[i](t) during the operation period of the storage battery 5[i], and the ambient temperature T[i](t).

[0093] The sharing adjustment rate setting unit 40 sets a target SOH predicted value at time (t+Δt) using the SOH predicted values ​​SOH[i](t+Δt) of all storage batteries 5[i] that constitute the battery system 1. The target SOH predicted value is a target deterioration evaluation value after Δt, for example, the average value of the deterioration evaluation values ​​of storage batteries 5[i], and is expressed as SOHave(t+Δt).

[0094] If the sharing adjustment rate of the storage battery 5[i] is α[i](t), the sharing adjustment rate α[i](t) is expressed by the following equation (10).

[0095] (10)

[0096] In equation (10), K is an adjustment gain. Further expanding equation (10) yields the following equation (11).

[0097] (11)

[0098] By applying the sharing adjustment rate α[i](t) in equation (11) to the charging / discharging power obtained by dividing the system required power Pall by the number of operating batteries N, i.e., by using equation (2), the individual power command for each operating battery can be calculated.

[0099] When it is desired to extend the system life until the target time (t+Δt), even if the sharing adjustment rate is calculated using the ambient temperature at that time (time t), the impact of the ambient temperature on the SOH occurs with a delay, so the ambient temperature is predicted in advance, and the sharing adjustment rate is calculated and applied when operating at that temperature without performing degradation suppression control. This makes it possible to keep the error after Δt low.

[0100] It is known that a lower temperature extends the battery life of the storage battery 5. Therefore, control may be performed to lower the temperature of the air conditioning in the section where the battery system 1 is installed, based on temperature information of the ambient temperature.

[0101] As described above, according to this embodiment, SOH varies depending on the ambient temperature, and the effect of ambient temperature on SOH does not appear in real time. However, by calculating a sharing adjustment rate that predicts the effect of ambient temperature on SOH, appropriate power sharing can be performed based on SOH and ambient temperature.

[0102] <Additional Notes> The battery control system, the power supply and demand system, the battery control method, and the battery control program described in the above-described embodiments can be understood, for example, as follows.

[0103] A battery control system (10) of a first aspect of the present disclosure is a battery control system applied to a battery system (1) having a plurality of storage batteries (5), and includes: a sharing adjustment rate setting unit (40) that acquires deterioration assessment information from a memory unit (60) in which deterioration assessment information associated with identification information and SOH of the storage batteries is stored, and sets a sharing adjustment rate using the SOH of the plurality of storage batteries; and a power command setting unit (50) that sets individual power commands for each of the storage batteries using the sharing adjustment rate, calculates a target SOH using the SOH of each of the storage batteries that constitute the battery system, and sets the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

[0104] Since the sharing adjustment rate of each storage battery is set based on the SOH, it is possible to appropriately share power so as to extend the life of the entire battery system, taking into account the SOH variation among the storage batteries. In particular, when the battery system is AC-linked, individual power commands can be directly input to the AC / DC converter to share power. Furthermore, appropriate power sharing can reduce the initial number of storage batteries installed in the battery system.

[0105] The battery control system of the second aspect of the present disclosure, in the first aspect, includes a degradation state evaluation unit (20) that sequentially selects storage batteries to be evaluated for their degradation state, and calculates a SOH related to the degradation state of the storage batteries to be evaluated using voltage values ​​or current values ​​when charging and discharging of the storage batteries to be evaluated according to a predetermined charge and discharge pattern, and the power command setting unit may use the sharing adjustment rate to set individual power commands for each operational storage battery that is a storage battery other than the storage battery to be evaluated.

[0106] The state of health can be calculated and used by the degradation state evaluation unit, and the storage battery being evaluated is excluded from the power sharing, so that an accurate power sharing can be calculated.

[0107] The battery control system of a third aspect of the present disclosure may be configured in the second aspect so that, of the storage batteries, those storage batteries that are currently suspended from charging or discharging may be excluded from the operational storage batteries.

[0108] In power sharing based on the SOH, it is possible to exclude dormant batteries from operational batteries and calculate accurate power sharing.

[0109] A fourth aspect of the battery control system of the present disclosure may be such that, in any one of the first to third aspects, the battery system is connected by a DC link to which each storage battery is directly connected, a command value is obtained by dividing an upper limit or lower limit of an allowable voltage range for a target voltage of the DC link by an upper limit charge / discharge power of the storage battery, and dividing the result by the sharing adjustment rate for each storage battery, and the power command setting unit sets the individual power command for each of the operational storage batteries using the command value for each storage battery.

[0110] By issuing power commands to each storage battery based on command values ​​calculated from the sharing adjustment rate to equalize the SOH, it is possible to control the SOH, which may vary, and extend the life of the entire battery system. Furthermore, by appropriately sharing power, it is possible to reduce the initial number of storage batteries installed in the battery system. In particular, when the battery system is a DC link, power sharing can be performed by inputting power commands based on the command values ​​to an AC / DC converter.

[0111] A battery control system of a fifth aspect of the present disclosure, in any of the first to fourth aspects, may calculate an SOH prediction value, which is a prediction value of the future SOH of each storage battery, using the SOH of each storage battery, the charge / discharge current and charging rate of the storage battery, and the ambient temperature, set a target SOH prediction value using the SOH prediction values ​​of all the storage batteries that make up the battery system, and set the sharing adjustment rate for each storage battery so as to bring the SOH prediction value of each storage battery closer to the target SOH prediction value.

[0112] SOH varies depending on the ambient temperature, and the effect of ambient temperature on SOH does not appear in real time. However, by calculating a sharing adjustment rate that predicts the effect of ambient temperature on SOH, appropriate power sharing can be performed based on SOH and ambient temperature.

[0113] A battery control system of a sixth aspect of the present disclosure may, in any of the first to fifth aspects, adjust the sharing adjustment rate of the storage battery and calculate the sharing adjustment rate using an adjustment gain that can be changed according to the deterioration state.

[0114] By using the adjustment gain, it is possible to calculate an appropriate sharing adjustment rate for each case.

[0115] A battery control system according to a seventh aspect of the present disclosure may be configured such that, in the sixth aspect, the adjustment gain is set to 1 and the allocation adjustment rate of each storage battery is set to a value corresponding to the SOH of each storage battery.

[0116] By setting the adjustment gain to 1, it is possible to calculate a sharing adjustment rate according to the SOH of each storage battery and share power. By sharing power according to the SOH, it is possible to align the amplitude of the state of charge (SOC) of each storage battery.

[0117] An electric power supply and demand system (100) according to an eighth aspect of the present disclosure includes a battery system including a plurality of storage batteries, and the battery control system according to any one of the first to seventh aspects.

[0118] A battery control method of a ninth aspect of the present disclosure is a battery control method applied to a battery system having a plurality of storage batteries, and includes a sharing adjustment rate setting process for acquiring deterioration assessment information from a memory unit in which deterioration assessment information associated with identification information and SOH of the storage batteries is stored, and setting a sharing adjustment rate using the SOH of the plurality of storage batteries, and a power command setting process for setting individual power commands for each of the storage batteries using the sharing adjustment rate, wherein a computer executes the process of calculating a target SOH using the SOH of each of the storage batteries that constitute the battery system, and setting the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

[0119] A battery control program according to a tenth aspect of the present disclosure causes a computer to execute the battery control method according to the ninth aspect.

[0120] While the present disclosure has been described above using embodiments, the technical scope of the present disclosure is not limited to the scope described in the above embodiments. For example, in the embodiments of the present disclosure, the degradation state evaluation unit 20 is provided and the load adjustment rate of the operating storage batteries other than the storage battery 5 to be evaluated is calculated. However, the degradation state evaluation unit 20 may not be provided and the load adjustment rate may be calculated for all operating storage batteries 5.

[0121] For example, the sharing adjustment rate setting unit 40 may exclude, from the operating batteries, any storage battery 5 that is currently suspended from charging or discharging. Whether or not a storage battery 5 is currently suspended from charging or discharging may be determined by, for example, acquiring the operation mode from each storage battery 5. For a storage battery 5 whose operation mode is suspended, the sharing adjustment rate setting unit 40 does not include the storage battery 5 in the calculation of the sharing adjustment rate.

[0122] DESCRIPTION OF SYMBOLS 1, 1a: Battery system 2: Power system 3: Substation 4: AC link 5 (5a to 5d): Storage battery 6: System monitoring system 7 (7a to 7d): Power conversion device 7' (7a' to 7d'): Power conversion device 8: DC link 9: AC / DC converter 10, 10a: Battery control system 11: CPU 12: Main memory device 13: Secondary memory device 14: Communication interface 15: Input device 16: Display 20: Degradation state evaluation unit 21: Selection unit 22: Measurement execution unit 23: Recovery control unit 24: Evaluation value calculation unit 30: Data management unit 40, 40a: Sharing adjustment rate setting unit 50, 50a: Power command setting unit 60: Storage unit 100, 100a: Power supply and demand system

Claims

1. A battery control system applicable to a battery system having a plurality of storage batteries, comprising: a sharing adjustment rate setting unit that acquires deterioration assessment information from a memory unit in which deterioration assessment information associated with identification information and SOH of the storage batteries is stored, and sets a sharing adjustment rate using the SOH of the plurality of storage batteries; and a power command setting unit that sets individual power commands for each of the storage batteries using the sharing adjustment rate, wherein the battery control system calculates a target SOH using the SOH of each of the storage batteries that constitute the battery system, and sets the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

2. A battery control system as described in claim 1, comprising a degradation state evaluation unit which sequentially selects storage batteries to be evaluated for their degradation state, and calculates a SOH relating to the degradation state of the storage batteries to be evaluated using the voltage value or current value when the charging and discharging of the storage batteries to be evaluated is controlled in accordance with a predetermined charging and discharging pattern, and the power command setting unit uses the sharing adjustment rate to set individual power commands for each operational storage battery that is a storage battery other than the storage battery to be evaluated.

3. A battery control system as described in claim 2, wherein among the storage batteries, a storage battery that is not being charged or discharged is excluded from the operational storage batteries.

4. The battery control system of claim 1, wherein the battery system is connected by a DC link to which each storage battery is directly connected, and a command value is obtained by dividing an upper or lower limit value of an allowable voltage range for a target voltage of the DC link by the upper limit charge / discharge power of the storage battery and dividing the result by the sharing adjustment rate for each storage battery, and the power command setting unit sets the individual power command for each of the operational storage batteries using the command value for each storage battery.

5. A battery control system as described in claim 1, which calculates a SOH prediction value, which is a prediction value of the future SOH of each storage battery, using the SOH of each storage battery, the charge / discharge current and charging rate of the storage battery, and the ambient temperature, sets a target SOH prediction value using the SOH prediction values ​​of all the storage batteries that constitute the battery system, and sets the sharing adjustment rate for each storage battery so as to bring the SOH prediction value of each storage battery closer to the target SOH prediction value.

6. A battery control system as described in claim 1, which adjusts the sharing adjustment rate of the storage battery and calculates the sharing adjustment rate using an adjustment gain that is changeable according to the deterioration state.

7. The battery control system according to claim 6, wherein the adjustment gain is set to 1, and the sharing adjustment rate of each of the storage batteries is set to a value corresponding to the SOH of each of the storage batteries.

8. An electric power supply and demand system comprising: a battery system having a plurality of storage batteries; and the battery control system according to claim 1.

9. A battery control method applicable to a battery system having a plurality of storage batteries, comprising: a sharing adjustment rate setting step of acquiring deterioration assessment information from a memory unit storing deterioration assessment information in which identification information and SOH of the storage batteries are associated, and setting a sharing adjustment rate using the SOH of the plurality of storage batteries; and a power command setting step of setting an individual power command for each of the storage batteries using the sharing adjustment rate, wherein a computer executes a step of calculating a target SOH using the SOH of each of the storage batteries constituting the battery system, and setting the sharing adjustment rate for each of the storage batteries so as to bring the SOH of each of the storage batteries closer to the target SOH.

10. A battery control program for causing a computer to execute the battery control method according to claim 9.

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