JP2018013435A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system for improving the estimation accuracy of full charge capacity without reducing the user convenience.SOLUTION: A power storage system 1 includes battery 3 and a control unit 9. In a time zone having a high frequency of use of the battery 3, the control unit determines the execution of full charge capacity estimation of the battery 3, when the lapsed time from the previous full charge capacity estimation or the integrated full discharge amount of the battery 3 from the previous full charge capacity estimation exceeds a first threshold. In a time zone having a low frequency of use of the battery 3, the control unit determines the execution of full charge capacity estimation, when the lapsed time or the integrated full discharge amount exceeds a second threshold lower than the first threshold.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage system.

  There exists a charger provided with the power converter which produces | generates desired electric power based on the electric power supplied from the system power supply, and the storage battery which stores the electric power produced | generated by the power converter. Such a charger is connected to the charger using, for example, the power output from the power conversion unit and the power output from the storage battery so that the power supplied from the system power supply does not exceed the contract power. Charge the storage battery to be charged. In the following description, a storage battery provided in the charger may be referred to as a charging storage battery, and a storage battery connected to the charger and charged may be referred to as a charging target storage battery.

  Since the full charge capacity of the storage battery decreases as the storage battery deteriorates over time, it is desirable that the full charge capacity of the storage battery be estimated after the storage battery is installed. The full charge capacity of the storage battery is estimated using, for example, a value (integrated current amount) obtained by integrating the current flowing through the storage battery during charging as in the following equation (1).

Fully charged capacity = Amount of accumulated current [Ah] / (Charging rate after charging is completed [%] − (Charging rate before starting charging [%])) (1)
In the method of estimating the full charge capacity of the storage battery using the accumulated current amount as shown in the equation (1), it is affected by the measurement error of the current sensor that measures the current flowing through the storage battery. Therefore, in order to reduce the influence of the measurement error of the current sensor, the charging rate (State Of Charge (SOC)) of the storage battery at the start of charging is reduced as much as possible, and the integrated current amount until the storage battery is fully charged is increased. It is possible to do.

  As a related technique, a technique described in Patent Document 1 is known.

Japanese Patent Laying-Open No. 2015-40832

  However, if the charging rate of the storage battery for charging is reduced unplanned in preparation for the estimation of the full charge capacity, when the charging target storage battery is connected to the charger, the charging target storage battery is charged with the output power from the charging storage battery. It becomes difficult to do. The power that can be generated and output by the power converter follows the contract power that can be received from the system power supply. Therefore, if sufficient power is not output from the storage battery for charging, the storage battery to be charged cannot be quickly charged, which is convenient for the user. Is damaged.

  The objective which concerns on one side of this invention is to provide the electrical storage system which improves the estimation precision of a full charge capacity, without reducing a user's convenience.

  A power storage system according to one aspect of the present invention includes a battery and a control unit. When the battery usage frequency is high, the control unit determines whether the battery has exceeded the first threshold when the elapsed time from the previous full charge capacity estimation or the accumulated charge / discharge amount of the battery from the previous full charge capacity estimation has exceeded the first threshold. To perform the full charge capacity estimation. In addition, the control unit determines to perform full charge capacity estimation when the elapsed time or the accumulated charge / discharge amount exceeds a second threshold value that is lower than the first threshold value in a time zone where the battery usage frequency is low.

  According to the power storage system according to the embodiment, it is possible to improve the estimation accuracy of the full charge capacity without reducing user convenience.

It is a figure which shows the structural example of the electrical storage system according to embodiment. It is a figure which shows an example of the processing flow of a full charge capacity estimation which the electrical storage system according to embodiment performs.

Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of a power storage system according to the embodiment. A charger 1 shown in FIG. 1 is an example of a power storage system according to the embodiment. In the example shown in FIG. 1, one charger 1 is connected to the system power supply P, but a plurality of chargers 1 may be connected to the system power supply P.

The charger 1 includes a power conversion unit 2, a storage battery 3 for charging, switches 4 to 6, a current sensor 7, a charging rate estimation unit 8, a control unit 9, and a storage unit 10.
The power conversion unit 2 charges the charging target storage battery B by converting the power output from the system power source P from alternating current to direct current and supplying the converted power to the charging target storage battery B. The power conversion unit 2 charges the charging storage battery 3 by converting the power output from the system power supply P from alternating current to direct current and supplying it to the charging storage battery 3. The storage battery B to be charged may be mounted on a vehicle such as an electric vehicle, a hybrid vehicle, or an electric forklift.

  The storage battery 3 for charging is an example of a battery according to the embodiment. The charging storage battery 3 is constituted by, for example, one or more lithium ion batteries, nickel metal hydride batteries, or electric double layer capacitors. The charging storage battery 3 charges the charging target storage battery B by supplying the stored power to the charging target storage battery B.

  The switches 4 to 6 are configured by, for example, a semiconductor switch such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an electromagnetic relay. The switch 4 is provided on the power line L1 that connects the power conversion unit 2 and the charging cable Ca, the switch 5 is provided on the power line L2 that connects the power conversion unit 2 and the charging storage battery 3, and the switch 6 is a charging storage battery. 3 and the charging cable Ca are provided on a power line L3.

  When the switch 4 is closed, the power output from the system power supply P is supplied to the charging target storage battery B through the power conversion unit 2. When the switch 5 is closed, the power output from the system power supply P is supplied to the charging storage battery 3 via the power conversion unit 2. When the switch 6 is closed, the power output from the charging storage battery 3 is supplied to the charging target storage battery B. Thus, in the configuration example shown in FIG. 1, the system power supply P and the charging storage battery 3 are provided as power supply sources for the charging target storage battery B.

The current sensor 7 may be configured by, for example, a hall element or a shunt resistor. The current sensor 7 detects a current flowing through the charging storage battery 3.
The charging rate estimation unit 8 is configured by, for example, a CPU (Central Processing Unit), a multi-core CPU, or a programmable device (FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device, etc.)). The charging rate estimation unit 8 estimates the charging rate (SOC) of the charging storage battery 3 based on the voltage of the charging storage battery 3 and the like. For example, the charging rate estimation unit 8 acquires information indicating a correspondence relationship between the open circuit voltage (OCV) of the charging storage battery 3 and the charging rate from the storage unit 10, and acquires the current storage battery 3. The current charging rate corresponding to the open circuit voltage may be obtained. The storage unit 10 is configured by, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). The charging rate estimation unit 8 may use the voltage of the charging storage battery 3 when the switch 5 is open as the current open circuit voltage of the charging storage battery 3. Further, the charging rate estimation unit 8 uses the closed circuit voltage (CCV) of the charging storage battery when the switch 5 is closed and a predetermined correction value, and the current open circuit of the charging storage battery 3. The voltage may be calculated.

  Moreover, the charging rate estimation part 8 calculates | requires integrated charge / discharge amount [Ah] of the storage battery 3 for charging by integrating | accumulating the electric current detected by the current sensor 7 during charging / discharging of the storage battery 3 for charging. For example, the charging rate estimator 8 integrates the current detected by the current sensor 7 during the estimation of the full charge capacity of the charging storage battery 3, that is, during charging of the charging storage battery 3. Current amount [Ah] is obtained. The charging rate estimation unit 8 adds the value obtained by dividing the accumulated current amount [Ah] during charging by the full charging capacity [Ah] to the charging rate before the start of charging, so that the charging battery 3 being charged is charged. You may ask for a charge rate.

  The control unit 9 includes a power supply control unit 91, a full charge capacity estimation determination unit 92, and a full charge capacity estimation unit 93. The charging rate estimation unit 8 may be included in the control unit 9. The control unit 9 is constituted by, for example, a CPU, a multi-core CPU, or a programmable device. For example, when the CPU, multi-core CPU, or programmable device executes a predetermined program, the charging rate estimation unit 8, the power supply control unit 91, the full charge capacity estimation determination unit 92, and the full charge capacity estimation unit 93 are realized. The

  The power supply control unit 91 obtains the power output from the system power supply P based on the output current of the system power supply P detected by the current sensor D. The current sensor D is composed of, for example, a Hall element or a shunt resistor. The power supply control unit 91 controls the operations of the power conversion unit 2 and the switches 4 to 6 so that the power output from the system power supply P does not exceed a power threshold (for example, contract power). The power supply control unit 91 controls the operation of the power conversion unit 2 and the switches 4 to 6, thereby supplying power from the system power supply P to the charging target storage battery B, supplying power from the system power supply P to the charging storage battery 3, And the electric power supply from the storage battery 3 for charge to the storage battery B to be charged is controlled.

  In addition, when it is determined to perform the full charge capacity estimation of the charging storage battery 3, the power supply control unit 91 sets the charging rate of the charging storage battery 3 at the start of the full charge capacity estimation to a preset estimated execution threshold value. In order to make it lower, charging of the charging storage battery 3 is refrained by opening the switch 5. By reducing the charging rate of the charging storage battery 3 at the start of the estimation of the full charge capacity below the estimated execution threshold value, it is possible to increase the integrated current amount during the full charge capacity estimation, that is, during charging. The influence of the measurement error of the sensor 7 can be reduced. For this reason, the estimation precision of the full charge capacity of the storage battery 3 for charge can be improved.

  The full charge capacity estimation determination unit 92 determines to perform full charge capacity estimation of the storage battery 3 for charging. The implementation of the full charge capacity estimation may be determined using a determination condition as to whether or not the elapsed time from the previous full charge capacity estimation of the charging storage battery 3 has exceeded a predetermined threshold value. Alternatively, the full charge capacity estimation may be performed using a determination condition as to whether or not the accumulated charge / discharge amount of the charging storage battery 3 from the previous full charge capacity estimation has exceeded a predetermined threshold.

  As a predetermined threshold value of the above-described determination condition, in a time zone in which the charging storage battery 3 is likely to be used for discharging to the charging target storage battery B, that is, in a time zone in which the charging storage battery 3 is used frequently, A first threshold is used. The first threshold value is that the full charge capacity (estimated full charge capacity) of the charge storage battery 3 estimated by the full charge capacity estimation unit 93 is different from the actual full charge capacity (actual full charge capacity) of the charge storage battery 3. It is a value set to suppress this. Moreover, as a predetermined threshold value of the above-described determination condition, a time zone in which the charging storage battery 3 is less likely to be used for discharging to the charging target storage battery B, that is, a time zone in which the usage frequency of the charging storage battery 3 is low. Is a second threshold that is lower (smaller) than the first threshold.

  For example, during the estimation of the full charge capacity, that is, during charging of the charging storage battery 3, discharge from the charging storage battery 3 to the charging target storage battery B is required due to a limitation due to a power threshold (for example, contract power). There may be cases. When such a case occurs, it is desirable that discharge from the charging storage battery 3 to the charging target storage battery B is started in order to give priority to the convenience of the user who wants to charge the charging target storage battery B quickly. When the discharge from the charging storage battery 3 to the charging target storage battery B is started, the full charge capacity estimation being performed is stopped.

  However, in the time zone when the usage frequency of the storage battery 3 for charging is low, there is a low possibility that the case described above will occur, and the possibility that the full charge capacity estimation during the implementation will be stopped is low. Therefore, in the time zone when the usage frequency of the charging storage battery 3 is low, the full charge capacity estimation determination unit 92 sets the determination condition to a value lower than the first threshold so that the full charge capacity estimation is performed as much as possible. A threshold of 2 is used to determine the implementation of full charge capacity estimation. That is, the full charge capacity estimation determination unit 92 determines to perform the full charge capacity estimation when the elapsed time from the previous full charge capacity estimation of the charging storage battery 3 exceeds the second threshold. Alternatively, the full charge capacity estimation determining unit 92 determines to perform full charge capacity estimation when the accumulated charge / discharge amount of the storage battery from the previous full charge capacity estimation exceeds the second threshold.

  On the other hand, in the time zone in which the storage battery 3 is used frequently, there is a high possibility that the above case will occur, and the full charge capacity estimation being performed is likely to be canceled. Therefore, it is conceivable that the full charge capacity estimation is not performed in a time zone in which the charging storage battery 3 is used frequently. However, when the full charge capacity estimation is not performed even in a time zone in which the charging storage battery 3 is used less frequently, the difference between the full charge capacity estimated value and the actual full charge capacity is widened. For example, when the usage frequency of the charging storage battery 3 increases during a time period when the usage frequency of the charging storage battery 3 is low due to a change in the usage pattern of the user, the situation where the full charge capacity estimation is not performed continues. The gap between the estimated charge capacity value and the actual full charge capacity widens. In addition, for example, when the time when the usage frequency of the charging storage battery 3 is low is short or when the user prohibits the charging of the charging target storage battery B in the time zone when the usage frequency of the charging storage battery 3 is low, The situation in which full charge capacity estimation is not performed continues, and the divergence spreads. Therefore, in a time zone in which the charging storage battery 3 is used frequently, the full charge capacity estimation determination unit 92 determines to perform full charge capacity estimation using the first threshold value as the determination condition. That is, the full charge capacity estimation determination unit 92 determines to perform the full charge capacity estimation when the elapsed time from the previous full charge capacity estimation of the charging storage battery 3 exceeds the first threshold. Alternatively, the full charge capacity estimation determination unit 92 determines to perform full charge capacity estimation when the accumulated charge / discharge amount of the storage battery from the previous full charge capacity estimation exceeds the first threshold. When the first threshold value is used, the full charge capacity estimation is performed to the extent necessary to suppress the estimated full charge capacity from deviating from the actual full charge capacity in a time zone in which the charging storage battery 3 is used frequently. Is implemented.

  The first threshold value and the second threshold value are stored in advance in the storage unit 10 in association with a time zone in which the usage frequency of the charging storage battery 3 is high and a time zone in which the usage frequency of the charging storage battery 3 is low. The full charge capacity estimation determination unit 92 reads a predetermined threshold value (first threshold value or second threshold value) corresponding to the current time from the storage unit 10, and uses the read predetermined threshold value as a determination condition. The execution of the full charge capacity estimation of the storage battery 3 is determined.

  In addition, the time zone when the usage frequency of the charging storage battery 3 is high and the time zone where the usage frequency of the charging storage battery 3 is low may be stored in the storage unit 10 in advance as fixed values. Further, the time zone in which the charging storage battery 3 is used frequently and the time zone in which the charging storage battery 3 is used low may be changed by the full charge capacity estimation determination unit 92 during the operation of the charger 1. For example, a time zone in which the accumulated charge / discharge amount of the charging storage battery 3 is greater than or equal to a predetermined value is set to a time zone in which the charging storage battery 3 is used frequently, and a time zone in which the accumulated charge / discharge amount is less than the predetermined value is charged. You may set to the time slot | zone when the usage frequency of the storage battery 3 is low. The accumulated charge / discharge amount of the charging storage battery 3 may be calculated by the charge rate estimation unit 8 and sent to the full charge capacity estimation determination unit 92.

When execution of full charge capacity estimation of the storage battery 3 for charging is determined, the full charge capacity estimation determination unit 92 instructs the full charge capacity estimation unit 93 to perform full charge capacity estimation of the storage battery 3 for charging.
When the full charge capacity estimation unit 93 is instructed to perform full charge capacity estimation from the full charge capacity estimation determination unit 92, the full charge capacity estimation unit 93 notifies the charge rate estimation unit 8 and the power supply control unit 91 of preparation for full charge capacity estimation. When the preparation for full charge capacity estimation is notified, the power supply control unit 91 lowers the charge rate of the storage battery 3 for charging at the start of full charge capacity estimation below a preset estimation execution threshold. Opening the switch 5 refrains from charging the storage battery 3 for charging. In addition, when preparation for full charge capacity estimation is notified, the charge rate estimation unit 8 sends the charge rate of the storage battery 3 for charge to the full charge capacity estimation unit 93 every elapse of a fixed time.

  When the charging rate of the charging storage battery 3 received from the charging rate estimation unit 8 becomes equal to or less than a preset estimation threshold, the full charge capacity estimation unit 93 starts the full charging capacity estimation and the power rate estimation unit 8 and power Notify the supply control unit 91. Upon receiving the notification of the start of full charge capacity estimation, the power supply control unit 91 closes the switch 5 in order to charge the storage battery 3 with the power supplied from the system power supply P via the power conversion unit 2, and performs charging. The switch 6 is opened to refrain from discharging the storage battery 3. In addition, when the notification of the start of the full charge capacity estimation is received, the charge rate estimation unit 8 sends the charge rate and integrated current amount of the storage battery 3 to the full charge capacity estimation unit 93 every time a fixed time elapses.

  The full charge capacity estimation unit 93 receives the charging rate and the accumulated current amount of the charging storage battery 3 from the charging rate estimation unit 8 and stores them in the storage unit 10. When the charge rate of the storage battery 3 for charging sent from the charge rate estimation unit 8 reaches the full charge rate (for example, 100 [%]), the full charge capacity estimation unit 93 is in a fully charged state. to decide. When it is determined that the charging storage battery 3 is in a fully charged state, the full charging capacity estimation unit 93 notifies the power supply control unit 91 of the end of charging of the charging storage battery 3. The power supply control unit 91 ends the charging of the storage battery 3 for charging by stopping the operation of the power conversion unit 2 or opening the switch 5.

  The full charge capacity estimation unit 93 estimates (calculates) the full charge capacity of the charging storage battery 3 using the above-described equation (1). That is, the full charge capacity estimation unit 93 calculates the accumulated current amount of the charging storage battery 3 during charging by the difference between the charging rate of the charging storage battery 3 at the end of charging and the charging rate of the charging storage battery 3 at the start of charging. By dividing, the full charge capacity of the charging storage battery 3 is estimated (calculated).

  An example of a processing flow of full charge capacity estimation executed by the power storage system according to the embodiment will be described. FIG. 2 is a diagram illustrating an example of a processing flow of full charge capacity estimation executed by the power storage system according to the embodiment.

  The full charge capacity estimation determination unit 92 acquires a predetermined threshold corresponding to the current time from the storage unit 10 (step S1). For example, if the current time is included in a time zone in which the charging storage battery 3 is used frequently, the predetermined threshold acquired is the first threshold. On the other hand, for example, if the current time is included in a time zone in which the charging storage battery 3 is used less frequently, the predetermined threshold to be acquired is the second threshold.

  The full charge capacity estimation determining unit 92 applies the acquired predetermined threshold value to the determination condition (step S2), and determines whether or not to perform the full charge capacity estimation of the charging storage battery 3. The determination condition used in step S2 may be a determination condition of whether or not the elapsed time from the previous full charge capacity estimation of the charging storage battery 3 has exceeded a predetermined threshold. The determination condition used in step S2 may be a determination condition as to whether or not the accumulated charge / discharge amount of the charging storage battery from the previous full charge capacity estimation exceeds a predetermined threshold.

  When it is determined not to perform the full charge capacity estimation of the storage battery 3 for charging (“No” in step S3), the series of processing returns to step S1. For example, when the elapsed time from the previous full charge capacity estimation of the charge storage battery 3 does not exceed a predetermined threshold, or the accumulated charge / discharge amount of the charge storage battery from the previous full charge capacity estimation does not exceed the predetermined threshold In this case, it is determined that the full charge capacity estimation of the charging storage battery 3 is not performed.

  On the other hand, when it is determined to perform the full charge capacity estimation of the charging storage battery 3 (“Yes” in step S3), the full charge capacity estimation determination unit 92 performs the full charge capacity estimation of the charging storage battery 3 fully charged. The capacity estimation unit 93 is instructed, and the series of processing proceeds to step S4. For example, when the elapsed time from the previous full charge capacity estimation of the charging storage battery 3 exceeds a predetermined threshold, or when the accumulated charge / discharge amount of the charging storage battery from the previous full charge capacity estimation exceeds a predetermined threshold Is determined to perform the full charge capacity estimation of the storage battery 3 for charging.

  In step S <b> 4, the full charge capacity estimation unit 93 notifies the power supply control unit 91 of preparation for full charge capacity estimation, and the received power supply control unit 91 opens the switch 5 to charge the charging storage battery 3. Refrain from. In addition, the full charge capacity estimation unit 93 notifies the charge rate estimation unit 8 of preparation for full charge capacity estimation, and the received charge rate estimation unit 8 determines the charge rate of the storage battery 3 for charging every certain time. The full charge capacity estimation unit 93 is sent.

  When the charging rate of the charging storage battery 3 received from the charging rate estimation unit 8 is equal to or lower than a preset estimation threshold (“Yes” in step S5), the full charge capacity estimation unit 93 starts full charge capacity estimation. Is notified to the charging rate estimation unit 8 and the power supply control unit 91. Receiving the notification, the power supply control unit 91 operates the power conversion unit 2 and closes the switch 5 to charge the charging storage battery 3 with the power supplied from the system power supply P (step S6). In addition, the power supply control unit 91 refrains from discharging the charging storage battery 3 during charging by opening the switch 6. In addition, the charging rate estimation unit 8 that has received the notification sends the charging rate and the accumulated current amount of the charging storage battery 3 to the full charge capacity estimation unit 93 at every elapse of a fixed time.

  After the full charge capacity estimation is started in step S6, when the full charge capacity estimation unit 93 receives a discharge request for the charging storage battery 3 from the power supply control unit 91 ("Yes" in step S7), the full charge capacity estimation is performed. The unit 93 stops the estimation of the full charge capacity being performed, and the series of processes ends. In this case, when the power supply control unit 91 receives a response notification indicating that the full charge capacity estimation is stopped from the full charge capacity estimation unit 93, the power supply control unit 91 starts discharging the storage battery 3 for charging by closing the switch 6. On the other hand, when the full charge capacity estimation unit 93 does not receive the discharge request of the charging storage battery 3 from the power supply control unit 91 (“No” in step S7), the series of processing proceeds to step S8.

  In step S8, when the charging rate of the charging storage battery 3 received from the charging rate estimation unit 8 by the full charging capacity estimation unit 93 is less than the full charging rate (“No” in step S8), the series of processing is performed in step S6. Return to. On the other hand, when the charging rate of the charging storage battery 3 received from the charging rate estimation unit 8 by the full charging capacity estimation unit 93 reaches the full charging rate (“Yes” in step S8), the series of processing proceeds to step S9.

  In step 9, the full charge capacity estimation unit 93 notifies the power supply control unit 91 of the end of charging of the charging storage battery 3 of the charging storage battery 3. Receiving the notification, the power supply control unit 91 terminates the charging of the charging storage battery 3 by stopping the operation of the power conversion unit 2 or opening the switch 5.

  The full charge capacity estimation unit 93 estimates the full charge capacity of the charging storage battery 3 using equation (1) (step S10). After the full charge capacity is estimated, the full charge capacity estimation unit 93 notifies the full charge capacity estimation determination unit 92 of the completion of the full charge capacity estimation, and the series of processes ends.

  As described above, when it is determined to perform the full charge capacity estimation, the charging of the charging storage battery 3 is refrained, and the charging rate of the charging storage battery 3 at the start of the full charge capacity estimation is equal to or less than the estimated execution threshold. Lowered. For this reason, it is possible to increase the integrated current amount during the full charge capacity estimation, that is, during the charging of the charging storage battery 3, reduce the influence of the measurement error of the current sensor 7, and fully charge the charging storage battery 3. The capacity estimation accuracy can be improved.

  In addition, the full charge capacity estimation is performed as much as possible in the time zone when the usage frequency of the charging storage battery 3 is low, and the full charge capacity estimation value is actually fulfilled in the time zone where the usage frequency of the charging storage battery 3 is high. This is done to the limit necessary to suppress the deviation from the charge capacity. For this reason, the convenience of the user who wants to use the storage battery 3 for charging in order to charge the storage battery B to be charged is not impaired.

Therefore, according to the power storage system according to the embodiment, it is possible to improve the estimation accuracy of the full charge capacity without reducing the convenience for the user.
In addition, this invention is not limited to the above embodiment, A various improvement and change are possible within the range which does not deviate from the summary of this invention.

  For example, in the example illustrated in FIG. 1, the implementation decision for estimating the full charge capacity of the charging storage battery 3, the estimation of the full charge capacity of the charging storage battery 3, and the charge / discharge control of the charging storage battery 3 are performed for the entire charger 1. This is performed by the control unit 9 that controls the control. However, the implementation decision for estimating the full charge capacity of the charging storage battery 3, the estimation of the full charge capacity of the charging storage battery 3, and the control of charging / discharging of the charging storage battery 3 control each part of the battery pack including the charging storage battery 3. It may be performed by the control unit. The control part which controls each part of a battery pack is comprised by CPU, multi-core CPU, or a programmable device, for example. In addition, when a plurality of chargers 1 are connected to the system power supply P, an execution decision for estimating the full charge capacity of the charging storage battery 3 included in each charger 1, an estimation of the full charge capacity of the charging storage battery 3, And control of charging / discharging of the storage battery 3 for charge may be performed by the control part which controls operation | movement of the several charger 1 via a communication network. The control part which controls operation | movement of the several charger 1 is comprised by a computer, for example.

  In the example shown in FIG. 1, a system power supply P is provided as a power supply source for the charging storage battery 3. However, instead of the system power supply P, an internal combustion engine (engine) that charges the charging storage battery 3 by regeneration may be provided. Thus, the power storage system according to the embodiment may be, for example, a hybrid vehicle using the charging storage battery 3 and the internal combustion engine as a power supply source for a load (for example, an electric motor).

DESCRIPTION OF SYMBOLS 1 Charger 2 Power conversion part 3 Rechargeable storage battery 4, 5, 6 Switch 7 Current sensor 8 Charge rate estimation part 9 Control part 10 Storage part 91 Power supply control part 92 Full charge capacity estimation determination part 93 Full charge capacity estimation part B Rechargeable storage battery Ca Charging cable D Current sensors L1, L2, L3 Power line P System power supply

Claims (3)

Battery,
In a time zone when the battery is used frequently, when the elapsed time from the previous full charge capacity estimation or the accumulated charge / discharge amount of the battery from the previous full charge capacity estimation exceeds the first threshold, the battery When it is determined that full charge capacity estimation is to be performed and the battery usage frequency is low, the full charge capacity is estimated when the elapsed time or the accumulated charge / discharge amount exceeds a second threshold value lower than the first threshold value. A power storage system including a control unit that determines execution of charge capacity estimation. The power storage system according to claim 1,
When the control unit determines to perform the full charge capacity estimation, the control unit refrains from charging the battery so that a charging rate of the battery is equal to or less than an estimated execution threshold. The power storage system according to claim 1 or 2,
The control unit stops the execution of the full charge capacity estimation when the battery starts to be discharged during the full charge capacity estimation.

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