JP2016070712A - Power storage device, control device, power storage system, control method and control program for power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device, a control device, a control method for the power storage device, and a control program for the power storage device for performing capacity measurement without impairing the convenience of a user of a lithium ion secondary battery.SOLUTION: The present invention has: a measurement unit for measuring the voltage of a battery module having one or a plurality of lithium ion secondary batteries; a charge-discharge unit for charging and discharging the battery module; a capacity measurement unit for measuring the battery capacity of the battery module; and a control unit for acquiring a discharge end voltage indicating a voltage in other than a charge and a discharge period, which is a period from the end of a discharge till the start of a next charge, and a reference voltage indicating a voltage for starting capacity measurement, and causing a charge to the battery module to stop when the discharge end voltage is higher than the reference voltage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage device, a control device, a power storage system, a control method for the power storage device, and a control program.

  There is a technology for estimating the full charge capacity of a battery using initial characteristics of an open circuit voltage (OCV) of a lithium ion secondary battery and a charge rate (SOC) of the battery (patent) Reference 1).

  However, a lithium ion secondary battery deteriorates due to repeated charging and discharging and the influence of storage temperature. When the lithium ion secondary battery deteriorates, the difference between the estimated full charge capacity and the actual full charge capacity gradually increases. As a result, the necessary power may not be charged / discharged. Therefore, it is important to detect the full charge capacity of the battery after deterioration.

  Techniques for detecting the full charge capacity of the secondary battery are described in Patent Documents 2 and 3, for example. In Patent Document 2, the storage capacity of a lithium ion secondary battery is estimated by integrating the amount of charge / discharge current from the time when the lithium ion secondary battery is in a fully discharged state to the time when it is in a fully charged state. Alternatively, the storage capacity is estimated by integrating the charge / discharge current from the time when the fully charged state is reached to the time when the fully discharged state is reached. On the other hand, the user of the lithium ion secondary battery discharges only necessary power from the power stored in the lithium ion secondary battery. In addition, the user charges the lithium ion secondary battery so that necessary power can be secured. For example, the user often sets the time period when the power demand of the load is small, the time period when the power purchase price is low, or the like as the charging period, and the lithium ion secondary battery is often charged every set charging period. Or it may charge frequently so that a fixed charge amount may be maintained. Therefore, when a lithium ion secondary battery is charged / discharged as requested by the user, the lithium ion secondary battery is not necessarily in a fully discharged state or a fully charged state within a predetermined period. In addition, depending on the specifications of the lithium ion secondary battery, there may be a case where it takes time to hinder use in order to obtain a fully discharged or fully charged state. That is, if the full charge state is set as a reference point for starting measurement of full charge capacity, measurement of full charge capacity may not be started. In addition, if the complete discharge state is set as a reference point for completing the measurement of the full charge capacity, the measurement of the full charge capacity may not be completed.

  Therefore, in Patent Document 3, a current integrated value from the time of detection of a reference point where the charging capacity is between 15 to 95% to the time of full charge voltage is measured. Further, the battery capacity from the charging capacity of 0 to the reference point is acquired from the table in which the reference point and the battery capacity are associated with each other. The acquired battery capacity and the integrated current value are added to obtain the full charge capacity of the lithium ion secondary battery.

JP 2010-196641 A JP 2013-347045 A JP 2012-145403 A

  In patent document 3, it discharges to the state in which the voltage of a lithium ion secondary battery becomes lower than the inflection point which is a reference point in the time slot | zone which does not operate | move a load apparatus at night etc. And a secondary battery is charged with the electric power which commercial power supplies, and a full charge capacity is detected. For this reason, in order to detect a full charge capacity, the discharge which the user of a lithium ion secondary battery does not require is performed.

  An object of the invention is to provide a power storage device, a control device, a control method for the power storage device, and a control program for the power storage device that perform capacity measurement without impairing the convenience of the user of the lithium ion secondary battery.

The control device of the present invention
A measuring unit for measuring a voltage of a battery module having one or more lithium ion secondary batteries;
A charging / discharging unit for charging and discharging the battery module;
A capacity measuring unit for measuring the battery capacity of the battery module;
Obtain a discharge end voltage indicating a voltage during a period other than during charging and discharging and indicating a voltage during a period from the end of discharging until the start of the next charging, and a reference voltage indicating a voltage at which capacity measurement is started,
And a controller that stops charging the battery module when the discharge end voltage is higher than the reference voltage.

The power storage device of the present invention is
A battery module having one or more lithium ion secondary batteries, and a control device for controlling charging and discharging of the battery module;
The control device
Obtain a discharge end voltage indicating a voltage during a period other than during charging and discharging and indicating a voltage during a period from the end of discharging until the start of the next charging, and a reference voltage indicating a voltage at which capacity measurement is started,
When the discharge end voltage is higher than the reference voltage, the charging of the battery module is stopped.

The power storage system of the present invention is
A battery module having one or more lithium ion secondary batteries, a power storage device having a control device for controlling charging and discharging of the battery module, a load connected to the power storage device, and a power supply source,
The power storage device
Charging is performed when the discharge end voltage, which is a voltage during a period other than during charging and discharging, and indicates a voltage during the period from the end of discharging to the start of the next charging, is higher than a reference voltage indicating a voltage at which capacity measurement is started. Stop.

The power storage device control method of the present invention includes:
A discharge end voltage indicating a voltage during a period other than during charging and discharging of a battery module having one or a plurality of lithium ion secondary batteries, and indicating a voltage during a period from the end of discharging to the start of the next charging; Get the reference voltage indicating the voltage to start the capacity measurement,
When the discharge end voltage is higher than the reference voltage, charging of the battery module is stopped.

The control program of the present invention is
On the computer,
End of discharge for obtaining a discharge end voltage indicating a voltage during a period other than during charging and discharging of a battery module having one or a plurality of lithium ion secondary batteries and indicating a voltage during a period from the end of discharging to the start of the next charging Voltage acquisition processing;
A reference voltage acquisition process for acquiring a reference voltage indicating a voltage for starting a battery module capacity measurement;
A charge stop process for stopping the charging of the battery module when the discharge end voltage is larger than the reference voltage;
Is executed.

The control device of the present invention
A measuring unit for measuring a voltage of a battery module having one or more lithium ion secondary batteries;
A charging / discharging unit for charging and discharging the battery module;
A capacity measuring unit for measuring the battery capacity of the battery module;
A control unit that acquires a capacity measurement signal that permits measurement of the battery capacity of the battery module and stops charging the battery module.

The power storage device of the present invention is
A battery module having one or more lithium ion secondary batteries, and a control device for controlling charging and discharging of the battery module;
The control device
A capacity measurement signal that permits measurement of the battery capacity of the battery module is acquired, and charging of the battery module is stopped.

  A power storage device, a control device, a power storage device control method, and a power storage device control program capable of measuring the battery capacity of a lithium ion secondary battery while ensuring the convenience of the power storage device can be provided.

It is a figure which shows an example of the functional block of the electrical storage apparatus in this embodiment. It is a figure which shows an example of the characteristic curve (terminal open circuit voltage curve) which shows the voltage (V) with respect to the charging rate of the lithium ion secondary battery in this embodiment. It is a flowchart which shows an example of operation | movement of the control apparatus in this embodiment. It is a figure which shows an example of the time change of the voltage of the electrical storage apparatus in this embodiment. It is a figure which shows an example of the display part of the electrical storage apparatus in this embodiment. It is a flowchart which shows an example of operation | movement of the control apparatus in this embodiment. It is a figure which shows an example of the time change of the voltage of the electrical storage apparatus in this embodiment.

Hereinafter, a power storage device according to an embodiment of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 shows an example of a functional block diagram of a power storage device 10 according to the present embodiment. The power storage device 10 in the present embodiment includes a battery module 20 that stores or discharges power, and a control device 30. The battery module 20 and the control device 30 are connected by a power line 40. The power line 20 connects the control device 30 and a power distribution system including a load that consumes power and a power supply source that supplies power. That is, the battery module 20 is connected to the power distribution system via the control device 30, discharged to the power distribution system, and charged from the power distribution system. In addition, the control device 30 may be connected to a network through the communication line 50 to transmit / receive information to / from the outside.

  The battery module 20 has a lithium ion secondary battery capable of storing and releasing electric power. The battery module 20 may have one lithium ion secondary battery (cell). Or you may have an assembled battery which connected the cell in series or in parallel. Furthermore, the battery module 20 may have a plurality of assembled batteries connected in series or in parallel.

  The power supply source supplies power to the power storage device 10. The power supply source is a device that generates power using thermal energy, kinetic energy, or chemical energy, and supplies the power to the load and the power storage device 10. The power supply source may be a power plant such as a power company, or may be a distributed power source owned and managed by a power consumer who uses power.

  The load is a device, facility, or facility that consumes power. The load is, for example, an electric device such as an air conditioner, a lighting, a computer. The load in the present embodiment is connected to the power storage device 10, and power is supplied from the power storage device 10.

  The control device 30 includes a measurement unit 31 that measures the voltage of the battery module 20, a charge / discharge unit 32 that enables connection between the battery module 20 and the power distribution system, and a control unit 33 that instructs the battery module 20 to charge and discharge. And a capacity measuring unit 34 for measuring the battery capacity of the battery module 20.

  The measurement unit 31 is connected to both ends of the terminal of the battery module 20 and measures the voltage of the battery module 20. Further, the discharge current from the battery module 20 and the charging current to the battery module 20 are measured. When the battery module is an assembled battery in which a plurality of lithium ion secondary batteries are connected in parallel, the plurality of lithium ion secondary batteries connected in parallel are regarded as one cell, and the voltage across one cell is measured. When the battery module is an assembled battery in which a plurality of lithium ion secondary batteries are connected in series, each lithium ion secondary battery is regarded as one cell, and the voltage across one cell is measured. For example, it is assumed that there is an assembled battery composed of a total of 32 cells of 4 cells in parallel and 8 cells in series. In this case, a cell connected in parallel is defined as one cell, and a voltage for 8 cells is measured assuming that 8 cells are connected in series.

  Further, SOC (State of Charge), DOD (Depth of Discharge), remaining charge and remaining discharge may be calculated using the measured voltage and current. The remaining charge is the amount of power that can be charged, the remaining discharge is the amount of power that can be discharged, and the sum of the remaining charge and the remaining discharge is the storage capacity.

  The measurement unit 31 transmits the measured voltage, current, SOC, and DOD to the control unit 34. Further, the measurement unit 50 transmits the measured voltage and current to the control unit 33 and the capacity measurement unit 34.

  The charging / discharging unit 32 charges and discharges the battery module 20 in accordance with instructions from the control unit 34. The charging / discharging unit 32 connects the power distribution system and the battery module 20, thereby discharging the power accumulated in the battery module 20 and charging the battery module 20 with power. The charge / discharge unit 32 converts AC power supplied from the distribution system into DC current, and also converts DC power discharged by the battery module 20 into AC current.

  For example, when a charge start instruction is acquired from the control unit 33, the charge / discharge unit 32 connects the battery module 20 and the power supply source. Alternatively, when a discharge instruction is acquired from the control unit 33, the charge / discharge unit 32 connects the battery module 20 and the load. When the charging end instruction or the discharging end instruction is acquired from the control unit 33, the charging / discharging unit 32 disconnects the connection between the battery module 20 and the load or power supply source.

  In addition, an abnormality may occur in the battery module 20 or the distribution system, and charging / discharging may not be performed safely. In this case, the charging / discharging unit 32 can stop charging and discharging without an instruction from the control unit 33. The charging / discharging unit 32 may hold in advance a condition for stopping charging and discharging.

  The control unit 33 instructs the battery module 20 to charge and discharge. The control unit 33 controls the charge / discharge unit 32 so as to charge or discharge the battery module 20 in accordance with the charge instruction or the discharge instruction. The method by which the control unit 33 acquires the charge instruction and the discharge instruction is not particularly limited. For example, the control unit 33 may acquire a charge instruction or a discharge instruction from an external server or the like via a network. Or you may hold | maintain previously the charging / discharging schedule which shows the period, date, and its output which the control part 33 performs charge or discharge.

  The control unit 33 uses the voltage acquired from the measurement unit 31 to determine whether or not to start capacity measurement for measuring the battery capacity of the battery module 20.

  The control unit 33 acquires from the measurement unit 31 a discharge end voltage that is a voltage during a period other than during discharging and during charging and that indicates a voltage during a period from the end of discharging to the start of charging. The control unit 33 compares the acquired discharge end voltage with the reference voltage.

  The reference voltage indicates a voltage at which capacitance measurement is started. For example, a voltage in a complete discharge state or a discharge end voltage can be used. Or the voltage set according to the characteristic of the lithium ion secondary battery may be sufficient. However, it is preferable that the voltage is close to a completely discharged state (charging rate 0%). By using a voltage close to complete discharge as the reference voltage, the battery capacity from the complete discharge state to the reference voltage can be easily calculated. Here, the completely discharged state indicates a state where the charging rate of the battery module 20 has reached 0%. The complete discharge state is also defined by the voltage of the cells constituting the battery module 20. A state in which the voltage of the cells constituting the battery module 20 reaches the lower limit voltage of a preset operation range may be set as a complete discharge state.

  The timing for determining whether or not to start the capacity measurement is not particularly limited. For example, the control unit 33 may hold a capacity measurement start schedule in advance. For example, a capacity measurement start schedule for determining whether or not capacity measurement can be started at a specific date and time may be held. Alternatively, the capacity measurement may be started when a deviation occurs between the estimated battery capacity and the actual battery capacity or when the instructed amount of power cannot be discharged.

  An example of the reference voltage is shown using FIG. FIG. 2 is a diagram illustrating an example of a characteristic curve (terminal open-circuit voltage curve) indicating a voltage (V) with respect to SOC (%) of a lithium ion secondary battery. In this example, for example, when the battery voltage becomes Va, the SOC is completely discharged with 0%. Further, in the terminal open circuit voltage curve, the slope of the voltage V varies greatly between SOC 0 to 20% and SOC 90 to 100. In the case of a lithium ion secondary battery having such a characteristic curve, the voltage Vb corresponding to the pole changing portion may be set as the reference voltage.

  The discharge end voltage is a voltage during a period other than during discharging and during charging, and indicates a voltage during a period from the end of discharging to the start of the next charging. The end of the discharge is different from the case where the voltage of the battery module 20 reaches a discharge end voltage that is a voltage for safely discharging avoiding overdischarge or reaching a complete discharge state corresponding to a charge rate of 0%. The end of discharge simply indicates that power supply from the battery module 20 to the power distribution system is completed. For example, the control unit 33 can determine that the discharge has ended due to the end of the discharge mode. In addition, discharge and charge here show the electric power supply-and-demand of the battery module 20 and a power distribution system. The self-discharge of the lithium ion secondary battery is not included in the discharge. The discharge end voltage may be a voltage at one point from the end of discharge to the start of the next charge, or may be an average value of the voltage from the end of discharge to the start of the next charge. Or you may acquire the voltage in the state which the charging / discharging part 32 received the discharge completion instruction | indication, and the state which is not connected with the distribution system after discharge.

  As another example, the power storage device 10 may set a period for charging the battery module 20 (charging period). In this case, the lowest voltage among the voltages at the start of a predetermined charging period or the dischargeable period indicating a period other than the charging period may be used as the discharge end voltage. The method for setting the charging period is not particularly limited. For example, a period when the purchase price of power supplied from the power supply source is low or a period when the power demand of the load is small may be preset as the charging period, or the charging period is started from the outside by a charging start signal. May be.

  If the discharge end voltage is equal to or lower than the reference voltage, the control unit 33 determines that capacity measurement is possible. The control unit 33 instructs the charging / discharging unit 32 to charge the battery module 20 to a capacity measurement end voltage indicating a voltage at which the capacity measurement is ended. Further, it instructs the capacity measuring unit 34 to start measuring the capacity of the battery module 20.

  The capacity measurement end voltage is a voltage for ending the capacity measurement. The capacitance measurement voltage is higher than the reference voltage. The capacity measurement end voltage is preferably a voltage in a fully charged state. Here, the fully charged state indicates a state where the battery module 20 is charged to a charging rate of 100%. The fully charged state is also defined by the voltage of the cells constituting the battery module 20. A state where the voltage of the cells constituting the battery module 20 reaches the upper limit voltage of the preset operation range may be set as a fully charged state.

  On the other hand, when the discharge end voltage is higher than the reference voltage, the control unit 33 determines that the capacity measurement cannot be started. The fact that the discharge end voltage is higher than the reference voltage means that the amount of power supplied to the load is smaller than the amount of charge charged in the charging period. For this reason, the dischargeable battery capacity of the power storage device 10 is limited. The controller 33 instructs the battery module 20 to stop charging. That is, the power storage device 10 is operated in a standby state in which no discharge or charging or discharging is performed until the discharge end voltage becomes equal to or lower than the reference voltage.

  It is assumed that the control unit 33 acquires a charging instruction for instructing charging of the battery module 20 from the outside during a period in which charging is stopped. In this case, the control unit 33 rejects the charging instruction. Further, information indicating that charging is stopped may be transmitted to the transmission source.

  Since the charging of the battery module 20 is stopped, the amount of charged power decreases as the power storage device 10 is operated. For this reason, compared with the case where charging and discharging are repeated, there is a higher possibility that the amount of charging power charged in the power storage device 10 will be smaller than the amount of discharging power to the load. That is, it is possible to increase the possibility that the discharge power amount is lower than the charge power amount and the discharge end voltage is equal to or lower than the reference voltage. As a result, it becomes easy to detect the full charge capacity.

  Control unit 33 may display on the display unit of power storage device 10 that charging is stopped. Or you may transmit the information which shows charge stop to an external server or the user and manager of the electrical storage apparatus 10 via a network.

  The capacity measuring unit 34 measures the battery capacity using the current and voltage acquired from the measuring unit 31. The capacity measuring unit 34 calculates the accumulated charging current by integrating the current charged in the period from the time when the discharge flow voltage is measured until the time when the battery module 20 reaches the fully charged state, thereby obtaining a full charge of the battery module 20. Measure the charge capacity. In charging during capacity measurement, the charging current value per unit time may change. However, it is desirable to perform control so as not to switch to discharging during charging. The method for measuring the battery capacity is not limited to this, and a known capacity measuring method can be used. Further, the capacity measuring unit 34 calculates the capacity maintenance rate (State of Health, SOH) using the battery capacity calculated by the capacity measuring unit 34 and the full charge capacity in a state where the capacity measuring unit 34 is unused and not deteriorated. Good. SOH in a state where the battery module 20 is not deteriorated is set to 100%. When the battery module 20 deteriorates, the SOH becomes smaller.

  The capacity measuring unit 34 transmits the calculated battery capacity and SOH to the control unit 33. The control unit 33 holds the acquired battery capacity in the storage unit. The control unit 33 can control charging and discharging of the battery module 20 based on the acquired battery capacity. In addition, the control unit 33 may display the remaining battery level on the basis of the acquired battery capacity on the display unit of the power storage device 10, or the remaining battery level may be transmitted to the user or administrator of the power storage device 10 via the network. You may send it.

  Operation | movement of the control apparatus 30 in this embodiment is demonstrated using FIG. 3 and FIG. FIG. 3 shows a flowchart of the operation of the control device 30 in the present embodiment. FIG. 4 is a diagram illustrating an example of a charge / discharge cycle of the power storage device 10. In the example illustrated in FIG. 4, the power storage device 10 charges the battery module 20 with electric power during a period from t0 to t1, and discharges electric power accumulated in the battery module 20 during a period from t1 to t2 and t3 to t4. The period from t2 to t3 is a standby period in which neither charging nor discharging is performed. In the period before t0, it is assumed that the battery module 20 is repeatedly charged and discharged within the range from the discharge lower limit voltage V2 to the charge upper limit voltage V1.

  In S <b> 10, the measurement unit 31 measures the voltage of the battery module 20. The measurement unit 31 acquires a discharge end voltage that is a voltage other than during charging and discharging and indicates a voltage from the end of discharging to the start of charging. The measurement unit 31 transmits the measured discharge end voltage to the control unit 33.

  In S <b> 11, the control unit 33 acquires the discharge end voltage from the measurement unit 31.

  In S12, the control unit 33 compares the discharge end voltage with a reference voltage indicating a voltage at which the capacity measurement is started. If the discharge end voltage is higher than the reference voltage, the process proceeds to S13. If the discharge end voltage is equal to or lower than the reference voltage, the process proceeds to S14.

  In S <b> 13, the control unit 33 instructs the charging / discharging unit 32 to stop charging the battery module 20. The charging / discharging unit 32 cuts off the connection between the battery module 20 and the power supply source. Alternatively, the charge / discharge unit 32 may fix the connection between the battery module 20 and the load.

  Thereafter, until the discharge end voltage becomes equal to or lower than the reference voltage, the power storage device 10 operates in a standby state in which no discharge or charging or discharging is performed. It is assumed that the control unit 33 acquires a charging instruction for instructing charging of the battery module 20 from the outside during a period in which charging is stopped. In this case, the control unit 33 rejects the charging instruction. Further, information indicating that charging is stopped may be transmitted to the transmission source.

  When the discharge end voltage is equal to or lower than the reference voltage, the control unit 33 instructs the capacity measurement unit 34 to start capacity measurement in S14. The capacity measurement unit 34 acquires the voltage and current of the battery module 20 from the measurement unit 32, and starts capacity measurement. In addition, when the charging to the battery module 20 is stopped, the control unit 33 releases the stop of the charging to the battery module.

  In S15, the control unit 33 instructs the charging / discharging unit 31 to charge the battery module 20 to the capacity measurement end voltage. The charging / discharging part 32 connects the battery module 20 and an electric power supply source, and starts charge.

  In the example shown in FIG. 6, it is assumed that the measurement unit 31 measures the discharge end voltage at t2 in S10. The discharge end voltage at t2 is higher than the reference voltage V0. Therefore, the control unit 33 instructs the charge / discharge unit 32 to stop charging the battery module 20 until t4 when the discharge end voltage becomes equal to or lower than the reference voltage V0. Since the discharge end voltage at t4 is equal to or lower than the reference voltage V0, the control unit 33 instructs the charge / discharge unit 32 to charge up to the capacity measurement end voltage V1.

  In the above description, the voltage of the battery module 20 is used as a reference for determining whether or not to start capacity measurement, but the present invention is not limited to this. The charging rate of the battery module 20 may be used as a reference. For example, it may be determined that the charging is stopped when the charging rate at the time when the discharging ends is larger than the reference capacity indicating the charging rate at which the capacity measurement is started.

  As described above, in the present embodiment, the charging of the battery module 20 is stopped until the discharge end voltage becomes equal to or lower than the reference voltage. According to this embodiment, the amount of charge of the power storage device 10 can be reduced. For this reason, compared with the case where it charges to the 1st charge upper limit voltage, possibility that the charge amount which charged the electrical storage apparatus 10 will be below the discharge amount to load becomes high. That is, it is possible to increase the possibility that the discharge end voltage becomes equal to or lower than the reference voltage. Accordingly, the capacity measurement can be performed without impairing the convenience of the user of the power storage device 10.

In addition, according to the present embodiment, forcible discharge is performed in order to start the capacity measurement, and the inconvenience that the user of the power storage device 10 cannot use the power stored in the power storage device 10 can be solved. . For example, it is possible to eliminate the inconvenience of charging again after forcibly discharging the power stored in a time zone where the power purchase price is low.
[Second Embodiment]
The determination of whether or not capacity measurement can be started may be started by an instruction from an administrator or user of the power storage device 10 or an alarm held by the power storage device 10. Therefore, in this embodiment, when the capacity measurement permission signal is received, the charging of the battery module 20 is stopped.

  An example of the power storage device 10 in the present embodiment can be represented in FIG. 1 as in the first embodiment. The power storage device 10 in this embodiment includes a battery module 20 and a control device 30. The control device 30 includes a measurement unit 31, a charge / discharge unit 32, a control unit 33, and a capacity measurement unit 34. In addition, below, description is abbreviate | omitted suitably about the function similar to 1st Embodiment.

  The measurement unit 31 is connected to both ends of the terminal of the battery module 20 and measures the voltage of the battery module 20. Further, the discharge current from the battery module 20 and the charging current to the battery module 20 are measured. The measurement unit 31 transmits the measured voltage and current measured to the control unit 33. Further, the measured voltage and current may be transmitted to the capacity measuring unit 34.

  The charging / discharging unit 32 charges and discharges the battery module 20 in accordance with instructions from the control unit 34. Moreover, the direct current which the battery module 20 discharged can be converted into an alternating current, and the alternating current supplied from the power distribution system can be converted into a direct current.

  The control unit 33 instructs the charging / discharging unit 32 to charge the battery module 20 and discharge from the battery module 20. Moreover, the control part 33 stops the charge to the battery module 20, when a capacity | capacitance measurement permission signal is received. Further, the control unit 33 acquires the discharge end voltage from the measurement unit 32. The control unit 33 compares the discharge end voltage with the reference voltage and determines whether or not capacity measurement can be started.

  When the discharge upper limit voltage is equal to or lower than the reference voltage, it is determined that the capacity measurement can be started. When determining that the capacity measurement can be started, the control unit 33 transmits a capacity measurement permission signal to the capacity measurement unit 34. Moreover, the control part 33 cancels | releases the stop of the charge to the battery module 20. FIG.

  On the other hand, when the discharge end voltage is higher than the reference voltage, it is determined that the capacity measurement cannot be started. The control unit 33 maintains the stop of charging the battery module 20. Thereafter, the charging is stopped until the discharge end voltage reaches the reference voltage.

  The capacity measurement permission signal is a signal for permitting or instructing the start of capacity measurement. Alternatively, it may be a signal permitting or instructing power storage device 10 to operate in the capacity measurement mode. As another example, it may be a signal indicating permission to stop charging the battery module 20. The capacity estimation mode may be a mode in which the control unit 33 starts determining whether or not to start capacity measurement. Alternatively, the capacity measurement unit 34 may perform a capacity measurement mode. Alternatively, the mode may include determination of whether or not to start capacity measurement and capacity measurement.

  The method by which the control unit 33 acquires the capacity measurement permission signal is not particularly limited. For example, a storage unit (not shown) of the control device 30 may hold a capacity measurement schedule indicating the date and time when capacity measurement starts in advance. The control unit 33 may acquire a capacity measurement schedule from the storage unit as a capacity measurement permission signal. Alternatively, a user or administrator of power storage device 10 may transmit a capacity measurement permission signal to power storage device 10. The control unit 33 can receive the capacity measurement permission signal via the network.

  Alternatively, the control unit 33 may display a display requesting permission to transmit the capacity measurement permission signal on the display unit of the power storage device 10 as illustrated in FIG. For example, when the control unit 33 receives a capacity measurement permission signal from a storage unit, an external server, or the like, a message such as “Do you want to allow the capacity measurement mode?” May be displayed on the display unit. When the “yes (permitted)” signal is received from the user of the power storage device 10, the operation in the capacity measurement mode can be started.

  The capacity measuring unit 34 measures the battery capacity using the current and voltage acquired from the measuring unit 31. The capacity measuring unit 34 transmits the calculated battery capacity and SOH to the control unit 33. The control unit 33 holds the acquired battery capacity in the storage unit. The control unit 33 can control charging and discharging of the battery module 20 based on the acquired battery capacity. In addition, the control unit 33 may display the remaining battery level on the basis of the acquired battery capacity on the display unit of the power storage device 10 or transmit the battery capacity to the user or administrator of the power storage device 10 via the network. May be.

  An example of the operation of the control device 30 in this embodiment will be described with reference to FIGS. 6 and 7. FIG. 5 shows a flowchart of the operation of the control device 30 in the present embodiment. FIG. 6 is a diagram illustrating an example of the voltage of the power storage device 10 at time t. 3 is a diagram illustrating an example of a charge / discharge cycle of the power storage device 10. FIG. In the example illustrated in FIG. 6, the power storage device 10 charges the battery module 20 with electric power during a period from t0 to t1, and discharges electric power accumulated in the battery module 20 during a period from t1 to t2 and t3 to t4. The period from t2 to t3 is a standby period in which neither charging nor discharging is performed. In the period before t0, the battery module 20 is repeatedly charged and discharged within the range from the discharge lower limit voltage V2 to the full charge voltage V1.

  In S20, the control unit 33 acquires a capacity estimation permission signal that is a signal for instructing capacity measurement. When acquiring the capacity measurement permission signal, the control unit 33 may instruct the power storage device 10 to operate in the capacity measurement mode. In the example shown in FIG. 6, it is assumed that the capacity measurement permission signal is received at time t1.

  In S <b> 21, the control unit 33 instructs the charging / discharging unit 32 to stop charging the battery module 20. The charging / discharging unit 32 cuts off the connection between the battery module 20 and the power supply source. Alternatively, the connection between the battery module 20 and the load may be fixed.

  In S22, the control unit 33 acquires from the measurement unit 31 a discharge end voltage that is a voltage other than during discharging and during charging, and indicates a voltage between the end of discharging and the start of charging.

  In S23, the control unit 33 determines whether or not capacity measurement can be started. The control unit 33 compares the discharge end voltage with a reference voltage V0 indicating a voltage for starting capacity measurement.

  When the discharge end voltage is higher than the reference voltage, the control unit 33 determines that the capacity measurement cannot be started. When it is determined that the capacity measurement cannot be started, the charging of the battery module 20 is stopped. Assume that the control unit 33 acquires a charging instruction for instructing charging of the battery module 20 from the outside via a network while charging is stopped. In this case, the control unit 33 rejects the acquired charging instruction. The control unit 33 may transmit information indicating that the charging instruction has been rejected to an external transmission source via the network. Thereafter, charging is stopped until the discharge end voltage becomes equal to or lower than the reference voltage.

  If the discharge end voltage is equal to or lower than the reference voltage, the process proceeds to S24. In S <b> 24, the control unit 33 instructs the charging / discharging unit 32 to cancel the charging stop of the battery module 20. The charging / discharging unit 32 may be connected so that the power supply source can supply power to the battery module 20. Alternatively, the connection between the load and the battery module 20 may be switched to the connection between the power supply source and the battery module 20.

  In S <b> 24, the control unit 33 transmits a capacity measurement permission signal to the capacity measurement unit 34 and causes the capacity measurement unit 34 to start capacity measurement. When the capacity measurement unit 34 acquires the capacity measurement permission signal, the capacity measurement unit 34 starts capacity measurement. The capacity measurement unit 34 acquires the reference voltage of the battery module 20 and the current at the reference voltage from the measurement unit 32.

In S25, the control unit 33 instructs the charging / discharging unit 31 to charge the battery module 20 to a capacity measurement end voltage indicating a voltage at which the capacity measurement is ended. The charge / discharge unit 32 is connected so that power can be supplied from the power supply source to the battery module 20. Further, the alternating current supplied from the power supply source is converted into a direct current and supplied to the battery module 20. The measurement unit 32 transmits the voltage and current of the battery module 20 being charged to the control unit 33 and the capacity measurement unit 34.
The capacity measuring unit 34 measures the battery capacity of the battery module using the acquired current and voltage of the battery module. Thus, the operation of the control device 30 is finished.

  As described above, according to the present embodiment, when the capacity measurement permission signal is received, the control unit 33 stops charging the battery module 20. According to the present embodiment as described above, the charging of the battery module 20 can be stopped before the discharge end voltage is acquired. Therefore, charging can be stopped regardless of the operation mode of the power storage device 10 (charging, discharging, standby). In addition, it is possible to reduce the processing amount of the control unit 33 in determining whether to start capacity measurement.

  In the present embodiment, the user of the power storage device 10 can confirm whether or not it is necessary to transmit a capacity measurement permission signal. According to such this embodiment, when the user of the power storage device 10 permits, it is possible to shift to the charge stop mode, so that charging can be stopped after reflecting the demand of the customer.

  The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Power storage device 20 Battery module 30 Control apparatus 31 Measurement part 32 Charging / discharging part 33 Control part 34 Capacity | capacitance measurement part 40 Power line 50 Communication line

Claims (9)

A measuring unit for measuring a voltage of a battery module having one or more lithium ion secondary batteries;
A charging / discharging unit for charging and discharging the battery module;
A capacity measuring unit for measuring the battery capacity of the battery module;
A voltage during a period other than during charging and discharging of the battery module, and a discharge end voltage indicating a voltage from the end of discharge until the start of the next charge, and a reference voltage indicating a voltage for starting capacity measurement are obtained. And
And a control unit that stops charging the battery module when the discharge end voltage is higher than the reference voltage. When the discharge end voltage is below a reference voltage,
The charge / discharge unit charges the battery module up to a capacity measurement end voltage indicating a voltage at which the measurement of the battery capacity of the battery module ends.
The capacity measuring unit starts measuring the battery capacity of the battery module;
The control device according to claim 1. A battery module having one or more lithium ion secondary batteries, and a control device for controlling charging and discharging of the battery module;
The controller is
A voltage during a period other than during charging and discharging of the battery module, and a discharge end voltage indicating a voltage from the end of discharge until the start of the next charge, and a reference voltage indicating a voltage for starting capacity measurement are obtained. And
When the discharge end voltage is higher than the reference voltage, the charging to the battery module is stopped.
Power storage device. A display unit for displaying information received from the control device;
The display unit displays information indicating that charging is stopped.
The power storage device according to claim 3. A battery module having one or a plurality of lithium ion secondary batteries; a power storage device having a control device for controlling charging and discharging of the battery module; a load connected to the power storage device; and a power supply source. ,
The power storage device
Charging is performed when the discharge end voltage, which is a voltage during a period other than during charging and discharging, and indicates the voltage during the period from the end of discharging until the start of the next charging, is higher than the reference voltage indicating the voltage at which capacity measurement starts. To stop the
Power storage system. A discharge end voltage indicating a voltage during a period other than during charging and discharging of a battery module having one or a plurality of lithium ion secondary batteries and from the end of discharging to the start of charging; and the capacity of the battery module Get a reference voltage indicating the voltage to start measuring,
When the discharge end voltage is higher than the reference voltage, the charging to the battery module is stopped.
A method for controlling a power storage device. On the computer,
End of discharge for obtaining a discharge end voltage indicating a voltage during a period other than during charging and discharging of a battery module having one or a plurality of lithium ion secondary batteries and indicating a voltage during a period from the end of discharging to the start of the next charging Voltage acquisition processing;
A reference voltage acquisition process for acquiring a reference voltage indicating a voltage to start voltage measurement of the battery module;
A charge stop process for stopping the charging of the battery module when the discharge end voltage is greater than the reference voltage;
To execute,
Control program. A measuring unit for measuring a voltage of a battery module having one or more lithium ion secondary batteries;
A charging / discharging unit for charging and discharging the battery module;
A capacity measuring unit for measuring the battery capacity of the battery module;
A control unit that obtains a capacity measurement signal that permits measurement of the battery capacity of the battery module and stops charging the battery module;
Control device. A battery module having one or more lithium ion secondary batteries, and a control device for controlling charging and discharging of the battery module;
The controller is
Obtaining a capacity measurement signal that permits measurement of the battery capacity of the battery module, and stopping charging to the battery module;
Power storage device.

Images