Battery control device, battery control method, and program

Abstract

To stop a storage battery unit that is no longer in use in a state suitable for storage and prevent expansion of a lithium-ion battery. [Solution] One aspect of the present disclosure is a storage battery control device that includes a control unit that controls charging and discharging of a storage battery, and a judgment unit that determines whether an index related to the life of the storage battery has exceeded a threshold value, and the control unit stops charging and discharging of the storage battery at a predetermined storage capacity when the judgment unit determines that the index has exceeded the threshold value.

Description

[Technical Field]

[0001] The present invention relates to a storage battery control device, a storage battery control method, and a program. [Background technology]

[0002] Storage battery systems equipped with a storage battery unit that stores power consumed in homes are becoming widespread. With these storage battery systems, for example, power generated by solar panels installed on the roof of a home can be used as household power. A known example of this type of technology is a battery pack and control method described in Patent Document 1. Patent Document 1 describes a technology that ensures safety by forcibly prohibiting charging and discharging of multiple battery cells according to the degree of degradation of each of them, since it is difficult to say that safety is sufficiently ensured when lithium-ion batteries deteriorate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-223872 Summary of the Invention [Problem to be solved by the invention]

[0004] When a storage battery unit containing a built-in lithium-ion battery is no longer in use due to deterioration, the storage battery unit may be left unused for a long period of time. When a storage battery unit is left unused for a long period of time, the lithium-ion battery may enter a deep discharge state due to self-discharge of the lithium-ion battery or dark current in the circuit board, causing the lithium-ion battery to expand and potentially causing deformation of the storage battery unit's case. Deformation of the storage battery unit's case can occur in any type of storage battery unit, whether cylindrical, prismatic, or pouch-type, and can be particularly noticeable in pouch-type storage battery units.

[0005] The present disclosure has been made in consideration of these circumstances, and aims to provide a battery control device, a battery control method, and a program that can stop a battery unit that is no longer in use in a state suitable for storage. [Means for solving the problem]

[0006] The present disclosure has been made to solve the above-mentioned problems, and one aspect of the present disclosure is a storage battery control device that includes a control unit that controls charging and discharging of a storage battery, and a judgment unit that determines whether an index related to the life of the storage battery has exceeded a threshold value, and the control unit stops charging and discharging of the storage battery at a predetermined storage capacity when the judgment unit determines that the index has exceeded the threshold value.

[0007] Another aspect of the present disclosure is a battery control method including the steps of: a battery control device determining whether an index related to the life of a battery has exceeded a threshold; when the battery control device determines that the index has exceeded the threshold, charging or discharging the battery so that the charge state of the battery is in a state suitable for storing the battery after the end of its life; and when the battery control device determines that the index has exceeded the threshold, stopping the charging and discharging of the battery at a predetermined storage capacity.

[0008] Another aspect of the present disclosure is a program that causes a computer of a control device to execute the steps of determining whether an index related to the life of a storage battery has exceeded a threshold, and, if it is determined that the index has exceeded the threshold, stopping charging and discharging of the storage battery at a predetermined storage capacity. [Effects of the Invention]

[0009] According to one aspect of the present invention, a storage battery unit that is no longer in use can be shut down in a state suitable for storage. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a block diagram showing an overview of a storage battery system 1 according to an embodiment. [Figure 2] 1 is a diagram illustrating an example of the configuration of a storage battery unit 10 according to an embodiment. [Figure 3] 2 is a block diagram showing an example of the configuration of a control module 12 according to the embodiment. FIG. [Figure 4] FIG. 3 is a diagram illustrating an example of a change in SOC in the storage battery system 1 according to the first embodiment. [Figure 5] 4 is a flowchart showing an example of an operation procedure in the storage battery system 1 of the first embodiment. [Figure 6] FIG. 10 is a diagram illustrating another example of changes in SOC in the storage battery system 1 according to the first embodiment. [Figure 7] 6 is a flowchart showing another example of the operation procedure in the storage battery system 1 according to the first embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of a change in SOH over time in a storage battery system 1 according to a second embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of a change in SOC during storage in a storage battery system 1 according to a second embodiment. [Figure 10] 10 is a flowchart showing an example of an operation procedure in a storage battery system 1 according to a second embodiment. [Figure 11] 10 is a flowchart showing an example of operation of a storage battery system 1 according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] A storage battery control device, a storage battery control method, and a program to which the present invention is applied will be described below with reference to the drawings.

[0012] <Overall system> FIG. 1 is a block diagram showing an overview of a storage battery system 1 according to an embodiment. The storage battery system 1 includes, for example, a storage battery unit 10, a power conditioner 20, and a solar panel 30. The power conditioner 20 is connected to a power grid 50 via a distribution board 40.

[0013] The storage battery unit 10 includes a plurality of battery cells and a storage battery control device (described later). The storage battery unit 10 charges the battery cells with power supplied from the power conditioner 20, and discharges the power stored in the battery cells and supplies it to the power conditioner 20.

[0014] The power conditioner 20 is connected to the storage battery unit 10 and the solar panel 30 via power lines and communication lines. The power conditioner 20 performs processes such as converting DC power to AC power, controlling the power supply voltage, and buying and selling electricity. The power conditioner 20 receives AC power from the power grid 50 via the distribution board 40, converts it into DC power, and supplies it to the storage battery unit 10. The power conditioner 20 receives DC power from the solar panel 30, performs voltage conversion, and supplies it to the storage battery unit 10. The power conditioner 20 receives DC power from the solar panel 30, converts the DC power into AC power, and supplies the AC power to the household appliances via the distribution board 40. The power conditioner 20 converts the DC power supplied from the storage battery unit 10 into AC power, and supplies the AC power to the household appliances via the distribution board 40. When the amount of charged power in the storage battery unit 10 is insufficient, the power conditioner 20 operates to purchase power from the power grid 50. In addition, when the power generated by the solar panel 30 is surplus, the power conditioner 20 operates to sell the power to the power grid 50.

[0015] The solar panel 30 receives sunlight to generate electricity and supplies DC power to the power conditioner 20.

[0016] FIG. 2 is a diagram illustrating an example of the configuration of the storage battery unit 10 according to the embodiment. The storage battery unit 10 is composed of, for example, seven storage battery modules 11-1 to 11-7 and a control module 12. The storage battery modules 11-1 to 11-7 are provided with a battery stack consisting of a plurality of storage battery units. The storage battery modules 11-1 to 11-7 are also provided with connectors 13-1 to 13-7 and connectors 14-1 to 14-7, respectively. The control module 12 measures the capacities of the storage battery modules 11-1 to 11-7 and stores the measured values ​​in a memory unit. The control module 12 is also provided with connectors 15-1 to 15-7 and connectors 16-1 to 16-7. In the following description, the storage battery modules 11-1 to 11-7 will be collectively referred to simply as "storage battery module 11."

[0017] Connectors 13-1 to 13-7 of storage battery modules 11-1 to 11-7 are connected by relay cables to connectors 15-1 to 15-7 of control module 12. Connectors 14-1 to 14-7 of storage battery modules 11-1 to 11-7 are connected to connectors 16-1 to 16-7 of control module 12 by relay cables.

[0018] FIG. 3 is a block diagram showing an example of the configuration of the control module 12 according to the embodiment. The control module 12 is equipped with a terminal block 121, a breaker 123, an HV (High-Voltage) board 124, and a BMS (Battery Management System) board 125.

[0019] The terminal block 121 is a connector that connects wiring from the power conditioner 20. The terminal block 121 is provided with a positive terminal 121a, a negative terminal 121b, and a ground terminal 121c. In this example, the ground terminal 121c is connected to the housing as a zero potential. Wiring extending from the positive terminal 121a and the negative terminal 121b of the terminal block 121 forms a charge / discharge line. The breaker 123 is for protection when a large current flows.

[0020] The communication connector 122 is a connector for connecting a shielded wire for communication from the power conditioner 20. The communication connector 122 is connected to a communication connector 126 on the BMS board 125. Data from the power conditioner 20 is received via the communication connector 122 and sent to the microprocessor 127. In addition, data from the microprocessor 127 is sent to the power conditioner 20 via the communication connector 122.

[0021] The HV board 124 is a board for charging and discharging the storage battery modules 11-1 to 11-7. On the HV board 124, a relay 1241, a current sensor 1242, a communication connector 1243, and connectors 15-1 to 15-7 are mounted.

[0022] The relay 1241 is a switch that energizes / disconnects the charge / discharge line of the storage battery unit 10. The current sensor 1242 detects the charge / discharge current to / from the storage battery modules 11-1 to 11-7. The communication connector 1243 is connected to the communication connector 128 on the BMS board 125. The communication connector 128 transmits the detected current of the current sensor 1242 to the microprocessor 127, for example.

[0023] Connectors 15-1 to 15-7 are terminals that connect to connectors 13-1 to 13-7 on the storage battery modules 11-1 to 11-7 side, respectively. Connectors 13-1 to 13-7 on the storage battery modules 11-1 to 11-7 side are connectors for charging and discharging, and wiring from both ends of storage battery units 10-1, 10-2, ..., 10-n that make up the battery stack is led out from connectors 13-1 to 13-7. Connectors 15-1 to 15-7 are connected in series to obtain the desired charging and discharging voltages. The positive electrode of connector 15-1, which has the highest potential, is connected to the charging and discharging line, and the negative electrode of connector 15-7, which has the lowest potential, is connected to the charging and discharging line.

[0024] BMS board 125 is a board for monitoring and controlling the states of storage battery modules 11-1 to 11-7. BMS board 125 is mounted with communication connectors 126 and 128, an AFE (Analog Front End) 129, a microprocessor 127, a photocoupler 130 which is an optical isolation element, and connectors 16-1 to 16-7.

[0025] The communication connector 126 is connected to the communication connector 122, and transmits and receives data to and from the power conditioner 20. The communication connector 128 is connected to the communication connector 1243, and transmits and receives data to and from the HV board .

[0026] AFE 129 detects the cell voltage of each of storage battery modules 11-1 to 11-7, and converts the detected cell voltage into digital data.

[0027] The microprocessor 127 performs various controls based on data from the power conditioner 20, data from the HV board 124, data from the AFE 129, and the like.

[0028] The optical isolation element is an element such as a photocoupler or a digital isolator, and connects the AFE 129 and the microprocessor 127. Since a high voltage is applied to the AFE 129, a photocoupler 130 provides isolation between the AFE 129 and the microprocessor 127.

[0029] Connectors 16-1 to 16-7 are terminals that connect to connectors 14-1 to 14-7 on the storage battery modules 11-1 to 11-7 side, respectively. Connectors 14 (14-1 to 14-7) are connectors for monitoring the cell voltages of storage battery units 10-1, 10-2, ..., 10-n. Connectors 16-1 to 16-7 transmit the cell voltages of storage battery modules 11-1 to 11-7 to the BMS board 125 side, respectively.

[0030] The microprocessor 127 is an example of a storage battery control device in which a processor such as a CPU (Central Processing Unit) executes a program stored in a program memory to realize functional units such as a control unit 1271 and a determination unit 1272. The control unit 1271 controls charging and discharging of the storage battery module 11. The determination unit 1272 determines whether an index related to the life of the storage battery module 11 has exceeded a threshold. When the determination unit 1272 determines that the index has exceeded the threshold, the control unit 1271 stops charging and discharging of the storage battery module 11 at a predetermined storage capacity.

[0031] The life of the storage battery module 11 is, for example, an EOL (End of Life), which indicates the time to replace or stop using the storage battery module 11. The time to replace or stop using the storage battery module 11 is set in advance in the storage battery unit 10 or the power conditioner 20. Alternatively, the time to replace or stop using the storage battery module 11 may be set in a storage unit or the like of a distribution server that can communicate with the storage battery unit 10 or the power conditioner 20, as described below, and the storage battery unit 10 or the power conditioner 20 may receive information indicating the time to replace or stop using the storage battery module 11 from the distribution server. The index relating to the lifespan of the storage battery module 11 is a value for determining whether the storage battery module 11 has reached the end of its lifespan. The index relating to the lifespan of the storage battery is, for example, SOH (State of Health). The SOH is a value representing the degree of deterioration of the storage battery module 11. The SOH of an unused, brand new storage battery module 11 is represented as 100%. The threshold is a value for determining whether the life of the storage battery module 11 has come to an end. For example, the threshold is set to 50% when the indicator is SOH.

[0032] The predetermined storage capacity is the charge capacity of the storage battery module 11 during the storage period of the storage battery module 11. The storage period of the storage battery module 11 is a period during which charging and discharging of the storage battery module 11 are stopped. The predetermined storage capacity is a preset value, for example, a preset SOC (State of Charge) value. The SOC is a value that represents the charge rate or state of charge of the storage battery module 11, and is defined as 100% when the storage battery module 11 is fully charged and 0% when the storage battery module 11 is fully discharged.

[0033] In the present embodiment, the capacity of the storage battery module 11 is described as SOC, but this is not limited thereto, and any other value may be used as long as it indicates the capacity of the storage battery module 11. For example, the capacity of the storage battery module 11 may be expressed by DOD (Depth of Discharge). DOD is the depth of discharge and indicates the ratio of the amount of discharge to the capacity of the storage battery module 11. When the storage battery module 11 is in a fully discharged state, the DOD is defined as 100%.

[0034] It is desirable that the control unit 1271 controls the storage capacity to a predetermined value, which is a capacity that prevents the storage battery module 11 from becoming deeply discharged during the storage period. The predetermined storage capacity is a capacity that corresponds to the storage period. For example, if the storage period is 10 years, the storage capacity may be SOC=10%, if the storage period is longer than 10 years, the storage capacity may be SOC higher than 10%, and if the storage period is shorter than 10 years, the storage capacity may be SOC lower than 10%. The storage period is a long period, such as 10 years, that is a preset period. Even when the life of the storage battery module 11 of the storage battery unit 10 has expired, there are cases in which the power conditioner 20 and the solar panel 30 are still in use, and in such cases, the storage battery module 11 of the storage battery unit 10 is left unused without being replaced. In the embodiment, a storage period is set during which charging and discharging of the storage battery module 11 is stopped, and deep discharge of the storage battery module 11 is prevented during the storage period. Since the storage battery module 11 becomes deep discharged when the SOC drops extremely, the control unit 1271 stops charging and discharging of the storage battery module 11 at a predetermined storage capacity to prevent deep discharge during the storage period, for example.

[0035] When stopping the charging and discharging of the storage battery module 11 at a predetermined storage capacity, if the capacity of the storage battery module 11 is not the predetermined storage capacity, the control unit 1271 controls the charging or discharging so that the capacity of the storage battery module 11 becomes the predetermined storage capacity. As a result, the capacity of the storage battery module 11 approaches the predetermined storage capacity. Thereafter, the control unit 1271 stops the charging and discharging of the storage battery module 11 when the capacity of the storage battery module 11 becomes the predetermined storage capacity. As a result, the control unit 1271 can stop the charging and discharging of the storage battery module 11 at the predetermined storage capacity.

[0036] When stopping charging and discharging of the storage battery module 11 at a predetermined storage capacity, the control unit 1271 may control the capacity of the storage battery module 11 so that the capacity is within a range from a lower limit capacity of the storage battery module 11 to the predetermined storage capacity. The lower limit capacity is a capacity within a range from 1% to 10% of the storage capacity. The lower limit capacity of the storage battery module 11 is a lower limit value of the SOC set during normal use when the storage battery module 11 is not yet deteriorated. The lower limit capacity may be within a range of 5% to 39%, and the storage capacity may be within a range of 10% to 40%. For example, when the lower limit capacity is SOC=5% and the storage capacity is SOC=10%, the control unit 1271 can control the capacity of the storage battery module 11 so that the capacity is higher than the lower limit capacity when charging and discharging of the storage battery module 11 is stopped at a predetermined storage capacity.

[0037] (First embodiment) A first embodiment of the above-described storage battery system 1 will be described below. FIG. 4 is a diagram illustrating an example of a change in SOC in the storage battery system 1 according to the first embodiment. FIG. 5 is a flowchart showing an example of an operation procedure in the storage battery system 1 according to the first embodiment. For example, assume that the time to determine the life of the storage battery module 11 arrives at time t1. In this case, the control unit 1271 charges the capacity of the storage battery module 11 to an upper limit value from time t1 to t2 (step S100). Thereafter, the control unit 1271 discharges the capacity of the storage battery module 11 to a lower limit value from time t2 to time t3 (step S102). The control unit 1271 calculates the amount of discharged power until the capacity changes from the upper limit value to the lower limit value by integrating the discharged power (parameter) while the storage battery module 11 is being discharged (step S104). The calculated amount of discharged power is the discharge capacity when the capacity of the storage battery module 11 changes from the upper limit value to the lower limit value, and corresponds to an index.

[0038] The determination unit 1272 determines whether the life of the storage battery module 11 has come, based on whether the calculated index exceeds a threshold value (step S106). If the determination unit 1272 determines that the index does not exceed the threshold value (step S106: NO), the control unit 1271 continues to use the storage battery module 11 (step S108) and ends the processing of this flowchart.

[0039] When the determination unit 1272 determines that the index exceeds the threshold value (step S106: YES), the control unit 1271 charges the storage battery module 11 from time t3 to time t4 and stops charging at a predetermined storage capacity (=storage SOC) (step S110). The control unit 1271 stops use of the storage battery module 11 when the storage battery module 11 has been charged to the predetermined storage capacity (step S112) and ends the processing of this flowchart. When the control unit 1271 stops use of the storage battery module 11, it may, for example, cause a remote control of the storage battery system 1 to display that use of the storage battery module 11 has been stopped.

[0040] FIG. 6 is a diagram showing another example of changes in SOC in the storage battery system 1 according to the first embodiment. FIG. 7 is a flowchart showing another example of the operation procedure in the storage battery system 1 according to the first embodiment. For example, assume that the time to determine the life of the storage battery module 11 arrives at time t1a. In this case, the control unit 1271 discharges the capacity of the storage battery module 11 to a lower limit value from time t1a to t2a (step S100A). Thereafter, the control unit 1271 charges the capacity of the storage battery module 11 to an upper limit value from time t2a to time t3a (step S102A). The control unit 1271 integrates the charging power (parameter) when the storage battery module 11 is being charged, thereby calculating the amount of charging power until the capacity changes from the lower limit value to the upper limit value (step S104A). The calculated amount of charging power is the charging capacity when the capacity of the storage battery module 11 changes from the lower limit value to the upper limit value, and corresponds to an index.

[0041] The determination unit 1272 determines whether the life of the storage battery module 11 has come, based on whether the calculated index exceeds a threshold value (step S106A). If the determination unit 1272 determines that the index exceeds the threshold value (step S106A: YES), the control unit 1271 continues to use the storage battery module 11 (step S108) and ends the processing of this flowchart.

[0042] When the determination unit 1272 determines that the index exceeds the threshold (step S106A: YES), the control unit 1271 discharges the storage battery module 11 from time t3a to time t4a and stops it at a predetermined storage capacity (=storage SOC) (step S110A). The control unit 1271 stops use of the storage battery module 11 when the storage battery module 11 has been discharged to the predetermined storage capacity (step S112) and ends the processing of this flowchart. When the control unit 1271 stops use of the storage battery module 11, it may, for example, cause a remote control of the storage battery system 1 to display that use of the storage battery module 11 has been stopped.

[0043] In the first embodiment, the index is calculated based on either the charge capacity or the discharge capacity, but this is not limited to this, and the index may be calculated based on both the charge capacity and the discharge capacity. Furthermore, the impedance of the storage battery module 11 due to the voltage change during charging or discharging may be measured to calculate the deterioration rate, and the deterioration rate may be used as the index. The storage battery system 1 may also utilize an existing deterioration monitoring function for the storage battery module 11. This deterioration monitoring function is a function for determining when to replace or stop using the storage battery module 11 as EOL, and is not limited to the process of determining when the storage battery module 11 has reached the end of its life, as described above.

[0044] As described above, according to the storage battery system 1 of the first embodiment, when it is determined based on the charge capacity or discharge capacity whether the storage battery module 11 has reached the end of its life, the SOC of the storage battery module 11 can be changed to the storage SOC before stopping use of the storage battery module 11. In this way, according to the storage battery system 1, the storage battery unit 10 that is no longer in use can be stopped in a state suitable for storage, and deformation such as expansion of the storage battery module 11 when the storage battery system 1 is left unused for a long period of time can be avoided.

[0045] (Second embodiment) A second embodiment of the above-described storage battery system 1 will now be described. FIG. 8 is a diagram showing an example of a change in SOH over time in the storage battery system 1 according to the second embodiment. In the second embodiment, the microprocessor 127 includes a memory unit 127a that stores a first numerical value indicating deterioration of the storage battery module 11 based on the charge / discharge cycle of the storage battery module 11, and a second numerical value indicating deterioration of the storage battery module 11 based on the period of use of the storage battery module 11. The determination unit 1272 calculates an index based on the first numerical value and the second numerical value stored in the memory unit 127a.

[0046] The control unit 1271 calculates a first numerical value indicating deterioration of the storage battery module 11 based on the charge / discharge cycles of the storage battery module 11. For example, charging the storage battery module 11 to 100% of its capacity is counted as one charge cycle. Specifically, if charging the storage battery module 11 to 20% of its capacity is performed five times, the control unit 1271 counts one charge cycle. Similarly, for example, discharging the storage battery module 11 to 100% of its capacity is counted as one discharge cycle. The charge / discharge cycles of the first numerical value are the sum of the charge cycles and the discharge cycles, but are not limited thereto, and the first numerical value may be the value of each of the charge cycles and the discharge cycles. The control unit 1271 updates the first numerical value stored in the memory unit 127a by monitoring the charging and discharging of the storage battery module 11.

[0047] The control unit 1271 may store in the storage unit 127a known parameters for calculating deterioration called cycle deterioration based on charge / discharge cycles of the storage battery module 11. This allows the control unit 1271 to read the parameters for calculating cycle deterioration from the storage unit 127a and calculate the first numerical value.

[0048] The control unit 1271 calculates a second numerical value indicating deterioration of the storage battery module 11 based on the usage period of the storage battery module 11. The second numerical value is calculated, for example, by referring to time information measured by a clock unit (not shown in FIGS. 1-3) built into the microprocessor 127. The control unit 1271 may calculate, for example, the elapsed time since the installation of the storage battery unit 10 as the usage period, or the operating time during which the storage battery module 11 is charging or discharging as the usage period.

[0049] The control unit 1271 may calculate the second numerical value based on the correspondence relationship between the SOC and the period of use of the storage battery module 11. For example, the control unit 1271 may store the period of use when the SOC is 0 to 33%, the period of use when the SOC is 34 to 66%, and the period of use when the SOC is 67 to 100%, and may multiply each period of use by a coefficient to calculate the deterioration level of the storage battery module 11 as the second numerical value.

[0050] The control unit 1271 may calculate the second numerical value based on the correspondence relationship between the SOC, temperature, and usage period of the storage battery module 11. The control unit 1271 acquires temperature information from a temperature sensor (not shown in FIGS. 1-3) that detects the temperature of the storage battery module 11, and stores the correspondence relationship between the SOC, temperature, and usage period in the storage unit 127a. The control unit 1271 may calculate the degree of deterioration of the storage battery module 11 as the second numerical value based on the SOC, temperature, and usage period.

[0051] The control unit 1271 may store in the storage unit 127a known parameters for calculating deterioration called calendar deterioration based on the period of use of the storage battery module 11. This allows the control unit 1271 to read the parameters for calculating calendar deterioration from the storage unit 127a and calculate the second numerical value.

[0052] The determination unit 1272 calculates an index based on the first numerical value and the second numerical value. The determination unit 1272 may calculate, for example, SOH as the index. The SOH may be a value calculated by a known method from at least one of cycle deterioration and calendar deterioration. As shown in FIG. 8, for example, the index calculated by the determination unit 1272 is calculated from the start of use of the storage battery unit 10 (t11), gradually decreases, and reaches a lower limit value at time t12. The lower limit value of the index is, for example, SOH=50%. When the index reaches the lower limit value, the determination unit 1272 determines that the life of the storage battery module 11 has arrived.

[0053] 9 is a diagram showing an example of changes in SOC during storage in the storage battery system 1 according to the second embodiment. In FIG. 9, A shows an example of changes in SOC of the storage battery module 11, and B shows another example of changes in SOC of the storage battery module 11. FIG. 10 is a flowchart showing an example of an operation procedure in the storage battery system 1 according to the second embodiment.

[0054] The control unit 1271 calculates a first numerical value and a second numerical value and stores them in the storage unit 127a (step S200), and calculates an index based on the first numerical value and the second numerical value (step S202). The determination unit 1272 determines whether the life of the storage battery module 11 has come, based on whether the calculated index exceeds a threshold value (step S204). If the index calculated by the determination unit 1272 does not exceed the threshold value (step S204: NO), the control unit 1271 continues to use the storage battery module 11 (step S206) and ends the processing of this flowchart.

[0055] If the control unit 1271 determines that the index calculated by the determination unit 1272 exceeds the threshold value (step S204: YES), the control unit 1271 determines whether the capacity of the storage battery module 11 is the storage SOC (step S208). If the capacity of the storage battery module 11 is the storage SOC (step S208: YES), the control unit 1271 stops use of the storage battery module 11 (step S212) and ends the processing of this flowchart. If the capacity of the storage battery module 11 is not the storage SOC (step S208: NO), the control unit 1271 charges or discharges the storage battery module 11 until the capacity becomes the storage SOC (step S210), stops use of the storage battery module 11 (step S212), and ends the processing of this flowchart. Note that the case where the capacity of the storage battery module 11 is the storage SOC may include, for example, a case where the capacity is within a predetermined tolerance range (for example, a deviation of about 1%) from the storage SOC.

[0056] For example, when the SOC of the storage battery module 11 is changing as shown by A in the figure, if the index calculated by the determination unit 1272 exceeds the threshold, the control unit 1271 starts discharging the storage battery module 11 from time t21 to bring the SOC of the storage battery module 11 closer to the storage SOC. Thereafter, when the SOC of the storage battery module 11 reaches the storage SOC at time t22, the control unit 1271 stops discharging the storage battery module 11.

[0057] For example, when the SOC of the storage battery module 11 is changing as shown in B in the figure, if the index calculated by the determination unit 1272 exceeds the threshold, the control unit 1271 causes the storage battery module 11 to charge from time t21, thereby bringing the SOC of the storage battery module 11 closer to the storage SOC. Thereafter, when the SOC of the storage battery module 11 reaches the storage SOC at time t30, the control unit 1271 stops charging the storage battery module 11.

[0058] As described above, according to the storage battery system 1 of the second embodiment, when the life of the storage battery module 11 has expired, the use of the storage battery module 11 can be stopped at the storage SOC based on an index based on cycle deterioration according to the charge / discharge cycle of the storage battery module 11 and calendar deterioration according to the period of use of the storage battery module 11. In this way, according to the storage battery system 1, the storage battery unit 10 that is no longer in use can be stopped in a state suitable for storage, and expansion of the storage battery module 11 when the storage battery system 1 is left unused for a long period of time can be avoided.

[0059] (Third embodiment) A third embodiment of the above-described storage battery system 1 will now be described. In the third embodiment, when a predetermined period of time has elapsed after prohibiting charging and discharging of the storage battery module 11, the control unit 1271 charges the storage battery module 11 so as to maintain the storage battery module 11 in a state for storage.

[0060] FIG. 11 is a flowchart showing an example of the operation of the storage battery system 1 according to the third embodiment. When charging / discharging of the storage battery module 11 is prohibited, the control unit 1271 starts timekeeping by the clock unit inside the microprocessor 127 (step S300). The control unit 1271 determines whether the period displayed by the clock unit has passed a predetermined period (step S302). The predetermined period is, for example, a storage period set at the time of designing the storage battery unit 10, and is, for example, 10 years, but is not limited to this, and may be a short period less than 10 years, such as 2 to 3 years. If the predetermined period has not passed, the control unit 1271 waits until the predetermined period has passed (step S302: NO), and if the predetermined period has passed, the control unit 1271 detects the SOC of the storage battery module 11 (step S304).

[0061] The control unit 1271 determines whether the detected SOC is equal to or less than a threshold value (step S306). The SOC threshold value is the SOC at which it is determined that the storage battery module 11 is in an over-discharge state, but is not limited to this and may be a value such as the lower limit value of the capacity of the storage battery module 11 described above. If the detected SOC is not equal to or less than the threshold value, the control unit 1271 waits until the next predetermined period. If the detected SOC is equal to or less than the threshold value, the control unit 1271 charges the storage battery module 11 until the SOC reaches the storage SOC (step S310).

[0062] As described above, according to the storage battery system 1 of the third embodiment, even if the SOC of the storage battery module 11 is set to the storage SOC when charging / discharging of the storage battery module 11 is prohibited, it is possible to avoid a subsequent decrease in the SOC of the storage battery module 11 and deep discharge.

[0063] In the above-mentioned embodiments, the first, second, and third embodiments have been described, but the storage battery system 1 may be equipped with any of the first, second, and third embodiments, and can be configured in an appropriate combination.

[0064] Note that a program for implementing the functions of the control unit 1271, the determination unit 1272, and the like may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be loaded into a computer system and executed to perform the processing described in the flowchart. Here, "loading a program recorded on a recording medium into a computer system and executing it" includes installing the program on a computer system. The term "computer system" here includes hardware such as an OS and peripheral devices. The term "computer system" may also include multiple computer devices connected via a network, including the Internet, a WAN, a LAN, a dedicated line, and other communication lines. The term "computer-readable recording medium" refers to portable media such as floppy disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into a computer system. Thus, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM. The recording medium may also include internal or external recording media accessible from a distribution server for distributing the program. The program code stored on the distribution server's recording medium may be different from the program code executable on a terminal device. In other words, the format in which the program is stored on the distribution server does not matter as long as it can be downloaded from the distribution server and installed in a form that is executable on the terminal device. The program may be divided into multiple parts, each of which may be downloaded at different times and then combined on the terminal device, or each of the divided programs may be distributed by a different distribution server. Furthermore, the term "computer-readable recording medium" also includes a storage medium that stores a program for a certain period of time, such as volatile memory (RAM) within a computer system that serves as a server or client when a program is transmitted over a network. The program may also be a program that realizes part of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that can realize the above-described functions in combination with a program already stored in the computer system. [Explanation of symbols]

[0065] 1. Battery storage system 10 Battery unit 11 Battery module 12 Control Module 13-1~13-7 Connectors 14-1~14-7 Connectors 15-1~15-7 Connectors 16-1~16-7 Connectors 20 Power conditioner 30 solar panels 40 Distribution board 43 Communication connector 50 Power system 52 Communication connector 121 Terminal block 122 communication connector 123 Breaker 124 HV board 125 BMS board 126 Communication connector 127 microprocessors 128 communication connector 129 AFE 130 Photocoupler 1241 Relay 1242 Current Sensor 1243 communication connector 1271 Control Unit 1272 Judgment section

Claims

1. a control unit that controls charging and discharging of the storage battery; a determination unit that determines whether an index related to the life of the storage battery has exceeded a threshold value; the control unit stops charging and discharging of the storage battery at a predetermined storage capacity when the determination unit determines that the index exceeds the threshold. Battery control device.

2. The battery control device according to claim 1 , wherein the control unit controls the storage capacity to a predetermined storage capacity that is a capacity that prevents the storage battery from becoming deeply discharged during a storage period.

3. 3. The battery control device according to claim 1, wherein the control unit controls the storage battery to charge or discharge so that the capacity of the storage battery becomes the predetermined storage capacity when the capacity of the storage battery is not the predetermined storage capacity, and stops charging and discharging of the storage battery when the capacity of the storage battery becomes the predetermined storage capacity.

4. 3. The battery control device according to claim 1, wherein the control unit controls the capacity of the storage battery so that the capacity is in a range from a lower limit capacity of the storage battery to a predetermined storage capacity, and the lower limit capacity is a capacity in a range from 1% to 10% of the storage capacity.

5. The battery control device according to claim 4 , wherein the lower limit capacity is within a range of 5% to 39%.

6. The battery control device according to claim 4 , wherein the storage capacity is within a range of 10% to 40%.

7. the control unit charges the storage battery to an upper limit value and then discharges the storage battery to a lower limit value; the determination unit determines whether the storage battery has reached the end of its life based on a discharge capacity when the capacity of the storage battery is changed by the control unit from an upper limit value to a lower limit value. The battery control device according to claim 1 or 2.

8. the control unit discharges the capacity of the storage battery to a lower limit value, and then charges the capacity of the storage battery to an upper limit value; the determination unit determines whether the storage battery has reached the end of its life based on the charge capacity at which the capacity of the storage battery has changed from a lower limit value to an upper limit value by the control unit; The battery control device according to claim 1 or 2.

9. a storage unit configured to store a first value indicating deterioration of the storage battery based on a charge / discharge cycle of the storage battery and a second value indicating deterioration of the storage battery based on a period of use of the storage battery; the determination unit calculates the index based on the first numerical value and the second numerical value stored in the storage unit; The battery control device according to claim 1 or 2.

10. 3. The battery control device according to claim 1, wherein the control unit charges the storage battery so as to maintain a storage state of the storage battery after a predetermined period of time has elapsed since prohibiting charging and discharging of the storage battery.

11. A step in which the battery control device determines whether an index related to the life of the battery exceeds a threshold; When the indicator exceeds the threshold value, the storage battery control device charges or discharges the storage battery so that the charge state of the storage battery is in a state for storing the storage battery after the end of its life. When the indicator is determined to exceed the threshold value, the storage battery control device stops charging and discharging of the storage battery at a predetermined storage capacity; A battery control method comprising:

12. The control device's computer determining whether an indicator relating to the life of the storage battery exceeds a threshold; When it is determined that the indicator has exceeded the threshold, stopping charging and discharging of the storage battery at a predetermined storage capacity when it is determined that the indicator has exceeded the threshold; A program that executes.

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