JP2022026240A - Power storage amount adjustment method, power storage device, and computer program - Google Patents

Abstract

To provide a power storage amount adjustment method, a power storage device, and a computer program that enable adjustment of the power storage amount even during discharging or charging.SOLUTION: In a power storage amount adjustment method, the power storage amount of a plurality of power storage cells 11 included in a power storage device 1 provided in an aircraft is adjusted. The OCV of each of the power storage cells 11 is acquired, a power storage amount difference indicating a difference in the power storage amount of each of the power storage cells 11 with respect to the minimum power storage amount is calculated on the basis of the OCV, and a discharge time required to discharge the electric amount corresponding to the power storage amount difference from each of the power storage cells 11 to the electric circuit 13 connected to the power storage cell 11 is calculated, and a current is passed through the electric circuit so as to consume the electric amount corresponding to the power storage amount difference to adjust the power storage amount of the storage cell 11, and when the cumulative time when the current flows through the electric circuit 13 connected to an arbitrary power storage cell reaches the discharge time, the adjustment of the power storage amount of an arbitrary storage cell 11 ends.SELECTED DRAWING: Figure 3

Description

The present invention relates to a storage amount adjusting method, a power storage device, and a computer program for adjusting the storage amount of a plurality of storage cells.

A power storage device configured by combining a plurality of power storage cells is used. When the storage amount of the storage cell varies due to the variation in the self-discharge amount of the storage cell and the voltage of the storage cell varies, the storage amount of the entire power storage device becomes small. In order to prevent variations in the voltage of the storage cells, in the conventional power storage device, the storage amount of the plurality of storage cells is adjusted to be substantially uniform. The amount of stored electricity is adjusted, for example, based on the voltage. When a discharge circuit is connected to each storage cell and there is a difference in voltage between multiple storage cells, the storage cell with a relatively high voltage is discharged, and the voltage of each storage cell becomes a relatively low voltage. Can be matched. Patent Document 1 discloses an example of a technique for adjusting the storage amount of a plurality of storage cells.

When adjusting the amount of electricity stored, OCV (Open Circuit Voltage) is used as the voltage of the electricity storage cell. When a current is flowing through the storage cell due to discharge or charging, the voltage of the storage cell changes from the OCV value, so it is difficult to accurately adjust the storage amount by adjusting the voltages of a plurality of storage cells. .. In particular, when the change in current is large, the deviation of the voltage of the storage cell from the OCV becomes large. Since the OCV is obtained in a non-current state in which neither charging nor discharging is performed to the outside of the power storage device, the storage amount is adjusted in the non-current state.

Japanese Unexamined Patent Publication No. 2015-208169

The power storage device mounted on the aircraft is removed from the aircraft, inspected, charged, and reattached to the aircraft when the aircraft is serviced on the ground. While the power storage device is removed from the aircraft, the power storage device can be in a non-current state and the storage amount can be adjusted. However, if the storage amount is adjusted while the power storage device is being removed from the aircraft, the period during which it is removed from the aircraft will be longer, other maintenance processes will be affected, and the time required for maintenance will be longer. Become. After the power storage device is attached to the aircraft, it may be discharged or charged, and it is difficult to obtain an opportunity to adjust the storage amount.

An object of the present invention is to provide a storage amount adjusting method, a power storage device, and a computer program capable of adjusting the storage amount even during discharging or charging.

The storage amount adjusting method according to one aspect of the present invention is a method of adjusting the storage amount of a plurality of storage cells included in the power storage device included in the aircraft, and acquires the OCV of each storage cell and is based on the acquired OCV. Then, the storage amount difference indicating the difference in the storage amount of each storage cell with respect to the minimum storage amount among the storage amounts of the plurality of storage cells is calculated for each storage cell, and the electric amount corresponding to the storage amount difference is calculated. The discharge time required to discharge from each storage cell for the electric circuit connected to each storage cell is calculated for each storage cell, and each storage cell consumes the amount of electricity corresponding to the storage amount difference. The amount of electricity stored in each storage cell is adjusted by passing a current through the electric circuit connected to the arbitrary storage cell, and the cumulative time during which the current flows through the electric circuit connected to the arbitrary storage cell is the accumulation of the time when the current flows through the arbitrary storage cell. When the discharge time calculated for is reached, the adjustment of the storage amount of the arbitrary storage cell is terminated.

The power storage device used in an aircraft according to one aspect of the present invention includes a plurality of power storage cells, an electric circuit connected to each power storage cell and consuming an amount of electricity by flowing an electric current, and a management unit. The management unit is an electric circuit connected to each storage cell with an amount of electricity corresponding to a difference in the amount of electricity stored, which indicates the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells. The discharge time required for discharging from each storage cell is stored for each storage cell, and a current is applied to the electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of storage. The storage amount of each storage cell is adjusted by flowing the current storage cell, and the cumulative time when the current flows through the electric circuit connected to the arbitrary storage cell reaches the discharge time calculated for the arbitrary storage cell. In this case, the adjustment of the storage amount of the arbitrary storage cell is completed.

The computer program according to one aspect of the present invention causes a computer to adjust the amount of electricity stored in a plurality of electricity storage cells included in the electricity storage device included in the aircraft. The computer program is connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of electricity stored, which indicates the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells. The amount of electricity stored in each storage cell is adjusted by passing a current through the electric circuit, and the cumulative amount of time that the current flows through the electric circuit connected to the arbitrary storage cell is the amount of electricity stored in the arbitrary storage cell. When the discharge time required for discharging the amount of electricity corresponding to the difference from the arbitrary storage cell to the electric circuit is reached, the computer is subjected to a process of ending the adjustment of the storage amount of the arbitrary storage cell. Let it run.

With the above configuration, the power storage device can adjust the power storage amount of the power storage cell even during discharging or charging. Therefore, there is an increased opportunity to adjust the amount of electricity stored in the electricity storage cell included in the electricity storage device provided in the aircraft.

It is a schematic diagram which shows the arrangement example of a power storage device. It is a block diagram which shows the structural example of a charge / discharge apparatus. It is a block diagram which shows the example of the internal structure of a power storage device, and the example of the function structure inside a BMU. It is a flowchart which shows the procedure of the process of specifying the full charge amount of a storage cell. It is a flowchart which shows the procedure of the process which makes the setting for adjustment of the storage amount. It is a figure which shows the example of the calculation result of the discharge time. It is a flowchart which shows the procedure of the process which adjusts the charge | storage amount of each charge cell.

In the storage amount adjustment method for adjusting the storage amount of a plurality of storage cells included in the power storage device of an aircraft, the OCV of each storage cell is acquired, and based on the acquired OCV, the storage amount of the plurality of storage cells is included. The storage amount difference indicating the difference in the storage amount of each storage cell with respect to the minimum storage amount is calculated for each storage cell, and the amount of electricity corresponding to the storage amount difference is applied to the electric circuit connected to each storage cell. The discharge time required for discharging from each storage cell is calculated for each storage cell, and a current is passed through the electric circuit connected to each storage cell so as to consume the amount of electricity corresponding to the difference in the amount of storage. When the cumulative amount of time that the current flows through the electric circuit connected to the arbitrary storage cell reaches the discharge time calculated for the arbitrary storage cell. The adjustment of the storage amount of the arbitrary storage cell is completed.

In the storage amount adjusting method, a difference in the amount of electricity stored in a plurality of storage cells is specified in a no-current state, and a discharge time required to discharge an amount of electricity corresponding to the difference in the amount of electricity stored from each storage cell is determined. The power storage device adjusts the storage amount of the storage cell by passing a current through an electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of storage during the discharge time. In order to determine the discharge time, it is necessary to measure the OCV, and the discharge time is determined in the no-current state. In the process of adjusting the storage amount of the storage cell, a current may be passed through the electric circuit so as to consume the amount of electricity corresponding to the difference in the amount of storage during the discharge time. It can be executed in any state. The power storage device mounted on the aircraft is removed from the aircraft during maintenance of the aircraft, inspected, and then attached to the aircraft. When the power storage device is attached to the aircraft, it may be discharged or charged. Since the amount of electricity stored can be adjusted even during charging or discharging, the amount of electricity stored can be adjusted even when the electricity storage device is attached to the aircraft. Therefore, there is an increased opportunity to adjust the amount of electricity stored in the electricity storage cell included in the electricity storage device provided in the aircraft. Further, the storage amount of the storage cell can be adjusted after the power storage device is attached to the aircraft, so that the period during which the power storage device is removed from the aircraft can be shortened. Therefore, the time required for aircraft maintenance is shortened.

In the storage amount adjusting method, the storage amount of each storage cell may be adjusted at the time of charging or discharging the plurality of storage cells. By adjusting the storage amount of the storage cell not only in the non-current state but also during discharging or charging, the opportunity to adjust the storage amount increases, and the storage amount of the storage cell can be adjusted in a short period of time.

In the storage amount adjusting method, when charging the plurality of storage cells, a part of the current supplied to each storage cell for charging is passed through the electric circuit connected to each storage cell, whereby the storage cell is charged. The amount of stored electricity may be adjusted. No current flows through the electric circuit connected to the storage cell with a small storage capacity. In a storage cell in which a current flows through a connected electric circuit, a part of the supplied electricity is consumed by the electric circuit, and the amount of electricity stored by charging increases as compared with a storage cell in which a current does not flow in the connected electric circuit. The amount is smaller. That is, the amount of electricity corresponding to the difference in the amount of electricity stored is consumed, and the difference in the amount of electricity stored becomes smaller.

In the storage amount adjusting method, when the plurality of storage cells are discharged, a part of the current supplied from each storage cell by the discharge is passed through the electric circuit connected to each storage cell, so that the storage amount of each storage cell is stored. May be adjusted. No current flows through the electric circuit connected to the storage cell with a small storage capacity. A storage cell in which a current flows through a connected electric circuit consumes a larger amount of electricity and has a larger decrease in the storage amount than a storage cell in which a current does not flow in the connected electric circuit. That is, the amount of electricity corresponding to the difference in the amount of electricity stored is consumed, and the difference in the amount of electricity stored becomes smaller.

In the storage amount adjusting method, the storage amount of each storage cell may be adjusted while the power storage device is attached to the aircraft. Since the storage amount of the storage cell can be adjusted after the power storage device is attached to the aircraft, the period during which the power storage device is removed from the aircraft is shortened. In the process of aircraft maintenance, the process performed after the power storage device is installed can be performed earlier, and the period required for aircraft maintenance is shortened.

In the storage amount adjusting method, a process of specifying a full storage amount representing the amount of electricity charged to the storage cell at the time of full charge is performed, and based on the OCV of each storage cell and the full storage amount, the plurality of storage cells The minimum storage amount among the storage amounts may be calculated, and the storage amount difference may be calculated for each storage cell based on the OCV of each storage cell and the minimum storage amount. By specifying the full storage amount of the storage cell, each storage is more accurate than when calculating the difference in storage amount without specifying the full storage amount, such as calculating using the initial value of the full storage amount. The difference in the amount of electricity stored in the cell can be calculated.

In the storage amount adjustment method, the voltage of each storage cell is measured when adjusting the storage amount of each storage cell, and when the voltage of any storage cell becomes equal to or lower than a specific voltage, the storage amount of the arbitrary storage cell is adjusted. Finish adjusting the amount of electricity stored. The specific voltage is a voltage corresponding to the amount of storage that the storage cell should maintain. By adjusting the amount of electricity stored, it is possible to prevent the amount of electricity stored in the electricity storage cell from decreasing too much, and the amount of electricity stored in the electricity storage cell is maintained at a certain level.

The power storage device used in an aircraft includes a plurality of power storage cells, an electric circuit connected to each power storage cell and consuming an amount of electricity by flowing an electric current, and a management unit. The management unit is an electric circuit connected to each storage cell with an amount of electricity corresponding to a difference in the amount of electricity stored, which indicates the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells. The discharge time required for discharging from each storage cell is stored for each storage cell, and a current is applied to the electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of storage. The storage amount of each storage cell is adjusted by flowing the current storage cell, and the cumulative time when the current flows through the electric circuit connected to the arbitrary storage cell reaches the discharge time calculated for the arbitrary storage cell. In this case, the adjustment of the storage amount of the arbitrary storage cell is completed. The power storage device adjusts the storage amount of the storage cell by passing a current through an electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of storage during the discharge time. The power storage device can adjust the amount of power stored in the power storage cell in any of the non-current states, charging, and discharging states.

In the power storage device, the management unit stores the full storage amount representing the amount of electricity charged in the storage cell at the time of full charge, acquires the OCV of each storage cell, and uses the OCV of each storage cell and the full storage amount as the storage amount. Based on this, the minimum storage amount among the storage amounts of the plurality of storage cells is calculated, and the storage amount difference is calculated for each storage cell based on the OCV of each storage cell and the minimum storage amount. The discharge time for each storage cell may be calculated based on the storage amount difference. By using the full storage amount of the storage cell, the difference in the storage amount of each storage cell can be calculated from the OCV.

The computer program causes the computer to adjust the storage amount of a plurality of storage cells included in the power storage device of the aircraft. The computer program is connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of electricity stored, which indicates the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells. The amount of electricity stored in each storage cell is adjusted by passing a current through the electric circuit, and the cumulative amount of time that the current flows through the electric circuit connected to the arbitrary storage cell is the amount of electricity stored in the arbitrary storage cell. When the discharge time required for discharging the amount of electricity corresponding to the difference from the arbitrary storage cell to the electric circuit is reached, the computer is subjected to a process of ending the adjustment of the storage amount of the arbitrary storage cell. Let it run. The power storage device adjusts the storage amount of the storage cell by passing a current through an electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the storage amount during the discharge time by a computer program. .. The power storage device can adjust the amount of power stored in the power storage cell in any of the non-current states, charging, and discharging states.

Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments thereof.
<Embodiment 1>
FIG. 1 is a schematic diagram showing an arrangement example of the power storage device 1. The power storage device 1 is provided in an aircraft 2 such as a passenger aircraft. The power storage device 1 supplies electric power to the load in the aircraft 2. When the aircraft 2 undergoes maintenance on the ground, the power storage device 1 is removed from the aircraft 2 and undergoes inspection. After the inspection, the power storage device 1 is connected to the charging / discharging device 3 and charged by the charging / discharging device 3. After charging is completed, the power storage device 1 is removed from the charging / discharging device 3 and attached to the aircraft 2. The power storage device 1 and the charge / discharge device 3 execute the storage amount adjusting method.

FIG. 2 is a block diagram showing a configuration example of the charging / discharging device 3. The power storage device 1 includes a plurality of power storage cells 11 and a BMU (Battery Management Unit) 22. The charging / discharging device 3 includes a control unit 31, a current supply unit 32, a discharge circuit 33, and a communication unit 34. The control unit 31 includes a calculation unit and a memory, and controls each unit of the charging / discharging device 3. The power storage device 1 is connected to the charge / discharge device 3 via a power line. The current supply unit 32 supplies a current to the power storage device 1 via the power line. For example, the current supply unit 32 is connected to an external distribution line of the charging / discharging device 3, and power is supplied through the distribution line to supply the current to the power storage device 1. The current supply unit 32 may have a transformer function or a power storage function. The discharge circuit 33 is a circuit for flowing the current supplied from the power storage device 1 by the discharge of the power storage device 1. By passing the current from the power storage device 1 through the discharge circuit 33, the charge / discharge device 3 can discharge the power storage device 1. The communication unit 34 is connected to the BMU 12 of the power storage device 1 via a communication line. The communication unit 34 transmits and receives various data and control signals to and from the BMU 12.

FIG. 3 is a block diagram showing an example of the internal configuration of the power storage device 1 and an example of the internal functional configuration of the BMU 12. The power storage device 1 includes a plurality of power storage cells 11. The plurality of storage cells 11 are connected in series. Each storage cell 11 is a cell. For example, the storage cell 11 is a lithium ion secondary battery. The storage cell 11 may be another secondary battery such as a lead storage battery. The amount of electricity stored is the amount of electricity stored in the electricity storage cell 11. A current sensor 14 is provided in the middle of the electric circuit connected to the plurality of storage cells 11. The current sensor 14 measures the current flowing through the plurality of storage cells 11.

An electric circuit 13 is connected to both ends of each storage cell 11. The electric circuit 13 includes a load 131 and a switch 132. For example, the load 131 comprises a resistor or a coil. The electric circuit 13 is a circuit for consuming an amount of electricity by flowing a current through the load 131. When the switch 132 is in the ON state, the load 131 is connected to both ends of the storage cell 11. When the switch 132 is turned on when the storage cell 11 is discharged, the current supplied from the storage cell 11 due to the discharge flows through the electric circuit 13, and the amount of electricity is consumed. If the switch 132 is turned on when the storage cell 11 is charged, a part of the current supplied from the outside of the storage cell 11 for charging flows through the electric circuit 13, and the amount of electricity is consumed. .. A sensor for measuring the current flowing through the electric circuit 13 is not provided.

The BMU 12 manages the states of the plurality of power storage cells 11 and controls each part of the power storage device 1. BMU12 corresponds to the management unit. The BMU 12 includes a calculation unit 121, a memory 122, a storage unit 123, a voltage acquisition unit 124, an interface unit 125, a communication unit 126, and a clock unit 127. The arithmetic unit 121 is, for example, a CPU (Central Processing Unit). The memory 122 stores information necessary for the calculation by the calculation unit 121. The storage unit 123 is non-volatile and stores various types of data. For example, the storage unit 123 is a non-volatile semiconductor memory.

The storage unit 123 stores the computer program 41. The computer program 41 is stored in the storage unit 123 by being read from a recording medium 40 such as an optical disk for storing the computer program 41 by a recording device (not shown) and written in the storage unit 123. The BMU 12 is a computer that allows the computer program 41 to execute the process. The arithmetic unit 121 executes the processing required for the BMU 12 according to the computer program 41. Alternatively, part or all of the processing executed by the BMU 12 may be executed by a method other than the method using the computer program 41. The storage unit 123 stores the full charge amount data and the time data, which will be described later.

The voltage acquisition unit 124 acquires the voltage between both ends of each storage cell 21. The voltage acquisition unit 124 acquires a voltage by measuring the voltage. Alternatively, the power storage device 1 includes a voltage sensor (not shown) that measures the voltage of each storage cell 21, and the voltage acquisition unit 124 acquires the value of the voltage measured by the voltage sensor. The interface unit 125 is connected to the current sensor 14. The interface unit 125 receives a signal related to the current measured by the current sensor 14, and the BMU 12 acquires a value of the current corresponding to the received signal. Further, the interface unit 125 is connected to a plurality of electric circuits 13. The arithmetic unit 121 controls each electric circuit 13 by transmitting a control signal for turning each switch 132 into an on state or an off state from the interface unit 125 to each electric circuit 13. The communication unit 126 communicates with the outside of the power storage device 1. For example, the BMU 12 communicates with the charging / discharging device 3 through the communication line by the communication unit 126. The clock unit 127 measures the passage of time.

The charging / discharging device 3 specifies the full storage amount of the storage cell 11 when charging the power storage device 1. The full storage amount represents the maximum amount of electricity that can be charged by the storage cell 11. Normally, the full storage amount decreases from the initial value with the passage of time. FIG. 4 is a flowchart showing a procedure of a process for specifying a full charge amount of the storage cell 11. Hereinafter, the step is abbreviated as S. The charge / discharge device 3 completely charges / discharges the power storage device 1, measures the amount of electricity discharged from the power storage cell 11, and calculates the full amount of electricity from the measured amount of electricity. (S11).

In S11, the control unit 31 transmits a control signal from the communication unit 34 to the BMU 12, causes the BMU 12 to fully charge the plurality of storage cells 11, and then causes the storage cells 11 to be completely discharged. The BMU 12 acquires the current flowing through the plurality of storage cells 11 and the voltage of each storage cell 11, and transmits the acquired current and voltage values from the communication unit 126 to the charging / discharging device 3. The control unit 31 controls the charging / discharging of the power storage device 1 based on the values of the current and the voltage received from the BMU 12. The charging / discharging device 3 charges each storage cell 11 by supplying a current from the current supply unit 32 to the power storage device 1. Further, the charging / discharging device 3 discharges each storage cell 11 by passing a current from the power storage device 1 through the discharge circuit 33. The control unit 31 calculates the current discharged from the plurality of storage cells 11 from the value of the current received from the BMU 12, and calculates the amount of electricity discharged from the plurality of storage cells 11 by complete discharge from the calculated current. .. The control unit 31 calculates the full storage amount of the storage cell 11 from the calculated electricity amount. The calculated full storage amount is the smallest full storage amount among the full storage amounts of the plurality of storage cells 11 connected in series. Alternatively, the charging / discharging device 3 may specify the full charge amount by other methods. For example, the BMU 12 stores the current history, and the charging / discharging device 3 calculates the full storage amount of the storage cell 11 based on the current history.

The BMU 12 stores the specified full charge amount (S12). In S12, the control unit 31 transmits the calculated value of the full charge amount from the communication unit 34 to the BMU 12. The BMU 12 receives the value of the fully stored amount in the communication unit 126, and the calculation unit 121 stores the fully stored amount data recording the received value of the fully stored amount in the storage unit 123. In S12, the BMU 12 may update the content of the full charge amount data.

The charging / discharging device 3 charges a plurality of storage cells 11 (S13). In S13, the charging / discharging device 3 charges a plurality of storage cells 11 by supplying a current from the current supply unit 32 to the power storage device 1. The charging / discharging device 3 and the BMU 12 end the process for specifying the full charge amount and charging. It should be noted that the processes S11 to S12 do not necessarily have to be performed each time charging is performed. For example, the processes S11 to S12 may be performed each time the aircraft 2 is operated a plurality of times and is charged a plurality of times.

The charging / discharging device 3 and the BMU 12 are set for adjusting the storage amount of the storage cell 11 in a non-current state in which the power storage device 1 is neither discharging nor charging. FIG. 5 is a flowchart showing a procedure of a process for making a setting for adjusting the amount of stored electricity. The BMU 12 determines that the power storage device 1 is in a non-current state (S21). In S21, the BMU 12 acquires the current measured by the current sensor 14 in the interface unit 125, and the calculation unit 121 is in a non-current state when the state in which the current value is equal to or less than a predetermined threshold value continues for a certain period of time. Is determined. The threshold value of the current and the value for a certain period of time are stored in the storage unit 123 in advance. Alternatively, the BMU 12 acquires the voltage of each storage cell 11 by the voltage acquisition unit 124, and the calculation unit 121 is in a non-current state when the state in which the amount of change in voltage is equal to or less than a predetermined threshold value continues for a certain period of time. It may be determined that. The threshold value of the amount of change in voltage is stored in the storage unit 123 in advance. The charging / discharging device 3 may transmit an instruction for determining the non-current state from the communication unit 34 to the BMU 12, and the BMU 12 may determine the non-current state according to the received instruction.

After determining that the power storage device 1 is in the no-current state, the BMU 12 acquires the OCV of each storage cell 11 by the voltage acquisition unit 124 (S22). The OCV is a voltage generated at both ends of the storage cell 11 when the circuit between both ends of the storage cell 11 is opened. For example, the OCV is a voltage generated at both ends of the storage cell 11 in a state where the storage cell 11 is neither discharged nor charged. The BMU 12 transmits the acquired OCV value from the communication unit 126 to the charging / discharging device 3.

The control unit 31 calculates the SOC (State of Charge) of each storage cell 11 based on the received OCV value (S23). SOC is a charge rate, which is a ratio of the amount of electricity stored in the electricity storage cell 21 to the amount of electricity stored in the electricity storage cell 11. The correspondence between OCV and SOC is stored in advance in the storage unit 123. The control unit 31 calculates the SOC of each storage cell 11 by reading the correspondence between the OCV and the SOC from the storage unit 123 and specifying the SOC corresponding to the OCV of each storage cell 11. The correspondence between OCV and SOC may be stored in the charging / discharging device 3.

Next, the control unit 31 calculates the amount of electricity stored in the electricity storage cell 11 (S24). In S24, the control unit 31 reads out the full storage amount data stored in the storage unit 123, and sets the value of the full storage amount recorded in the full storage amount data as the full storage amount of each storage cell 11 to each full storage amount. By multiplying the SOC of the storage cell 11, the storage amount of each storage cell 11 is calculated.

Next, the control unit 31 calculates a storage amount difference indicating the difference in the storage amount of each storage cell 11 with respect to the minimum storage amount among the storage amounts of the plurality of storage cells 11 (S25). In S25, the control unit 31 selects the minimum storage amount from the calculated storage amounts of the plurality of storage cells 11, and subtracts the minimum storage amount from the storage amount of each storage cell 11 to obtain each storage cell. The difference in the amount of electricity stored in 11 is calculated. By using the specified full storage amount, it is possible to calculate the storage amount difference of each storage cell 11 more accurately than when the current full storage amount is not used, such as using the initial value of the full storage amount. ..

Alternatively, in S24, the control unit 31 calculates the minimum storage amount, and in S25, the difference between the SOC of the storage cell 11 having the minimum storage amount and the SOC of another storage cell 11 is used as the full storage amount. By multiplying, the difference in the amount of electricity stored in each electricity storage cell 11 may be calculated. The storage cell 11 having the minimum storage amount is the storage cell 11 having the minimum OCV. Alternatively, in S25, the control unit 31 calculates the storage amount difference of each storage cell 11 based on the difference between the OCV of the storage cell 11 having the minimum storage amount and the OCV of another storage cell 11. May be good.

Next, the control unit 31 calculates the discharge time required to discharge the electric quantity corresponding to the storage amount difference from the storage cell 11 to the electric circuit 13 (S26). In S26, the control unit 31 supplies the electric current from the electricity storage cell 11 to the electric circuit 13 connected to the electricity storage cell 11, so that the time required for consuming the amount of electricity corresponding to the difference in the amount of electricity stored is the discharge time. Calculate as. For example, the resistance value of the load 131 included in each electric circuit 13 is stored in the storage unit 123 in advance, and the control unit 31 reads out the resistance value of the load 131. The control unit 31 calculates the value of the current flowing through the electric circuit 13 when each storage cell 11 is discharged from the OCV of the storage cell 11 and the resistance value of the load 131. For example, the control unit 31 calculates the current value assuming that the same voltage as the OCV of the storage cell 11 is applied to the load 131. The control unit 31 calculates the discharge time based on the difference in the amount of charge stored in the storage cell 11 and the calculated current value. The control unit 31 calculates the discharge time for each storage cell 11.

FIG. 6 is a chart showing an example of the calculation result of the discharge time. In the example shown in FIG. 6, the power storage device 1 includes four power storage cells A, B, C, and D. The OCV of each storage cell 11 is acquired, and the SOC is obtained. The unit of SOC is%. The amount of electricity stored can be obtained from the SOC and the amount of electricity stored. In the example shown in FIG. 6, the unit of the stored storage amount is Ah (at amp-hours), and the full stored amount is 50 (Ah). Among the four storage cells 11, the storage amount of the storage cell A is the smallest. The value obtained by subtracting the storage amount of the storage cell A from the storage amount of the other storage cells 11 is the storage amount difference. The discharge time is calculated from the difference in the amount of stored electricity. In the example shown in FIG. 6, the unit of the discharge time is h (time), and the resistance value of the load 131 is 50Ω. When the unit of the stored amount is Ah, the discharge time is calculated by dividing the value of the stored amount difference by the calculated current value. In the storage cell 11 having a large difference in storage amount, the discharge time becomes long.

The BMU 12 stores the calculated discharge time for each storage cell 11 (S27). In S27, the control unit 31 transmits the calculated discharge time value from the communication unit 34 to the BMU 12. The BMU 12 receives the discharge time value of each storage cell 11 in the communication unit 126, and the calculation unit 121 stores the time data in which the received discharge time value is recorded in the storage unit 123. In the time data, the discharge time for each storage cell 11 is recorded. The charging / discharging device 3 and the BMU 12 complete the setting process.

After the completion of S21 to S27, the power storage device 1 is removed from the charging / discharging device 3 and attached to the aircraft 2. With the power storage device 1 attached to the aircraft 2, the BMU 12 adjusts the power storage amount of each storage cell 11. The BMU 12 may perform a process of adjusting the storage amount of each storage cell 11 in a no-current state. In the BMU 12, when the power storage device 1 is charging by supplying a current to the plurality of power storage cells 11 from the outside of the power storage device 1, or the current is supplied from the plurality of power storage cells 11 to the outside of the power storage device 1. As a result, when the power storage device 1 is discharging, a process of adjusting the power storage amount of each storage cell 11 may be performed. The BMU 12 may perform a process of adjusting the storage amount of each storage cell 11 under specific conditions. For example, the BMU 12 may perform a process of adjusting the storage amount of each storage cell 11 only when the power storage device 1 is charging.

FIG. 7 is a flowchart showing a procedure of a process for adjusting the storage amount of each storage cell 11. The arithmetic unit 121 executes the following processing according to the computer program 41. The calculation unit 121 starts adjusting the storage amount of each storage cell 11 (S31). In S31, the calculation unit 121 adjusts the storage amount of the plurality of storage cells 11 in parallel. The calculation unit 121 passes a current through the electric circuit 13 connected to each storage cell 11 so as to consume an amount of electricity corresponding to the difference in the amount of electricity stored in each storage cell 11. More specifically, the arithmetic unit 121 controls the switch 132 through the interface unit 125 to turn on the switch 132, thereby causing a current to flow through the electric circuit 13. Of the plurality of storage cells 11, the calculation unit 121 does not adjust the storage amount for the storage cell 11 having the minimum storage amount. That is, the arithmetic unit 121 turns off the switch 132 included in the electric circuit 13 connected to the electric storage cell 11 having the minimum electric storage amount, and does not allow current to flow through the electric circuit 13. The calculation unit 121 causes the clock unit 127 to measure the time when a current is passed through the electric circuit 13 for each storage cell 11. The BMU 12 does not acquire the value of the current flowing through the electric circuit 13.

In the no-current state, when the switch 132 is turned on, the storage cell 11 is discharged, and the current supplied from the storage cell 11 flows through the electric circuit 13. As the current flows through the electric circuit 13, the amount of electricity is consumed, and the amount of electricity stored in the storage cell 11 decreases. Since no current flows through the electric circuit 13 connected to the storage cell 11 having the minimum storage amount, the other electric circuits 13 consume the amount of electricity corresponding to the difference in the storage amount. As a result, the difference in the amount of electricity stored becomes small.

When the power storage device 1 is discharged, the plurality of power storage cells 11 supply a current to the outside of the power storage device 1. At this time, when the switch 132 is turned on, a part of the current supplied from the storage cell 11 by the discharge flows through the electric circuit 13. In the storage cell 11 in which the current flows through the connected electric circuit 13, a larger amount of electricity is consumed and the decrease in the storage amount is larger than in the storage cell 11 in which the current does not flow in the connected electric circuit 13. That is, the amount of electricity corresponding to the difference in the amount of electricity stored is consumed, and the difference in the amount of electricity stored becomes smaller.

When the power storage device 1 is charged, current is supplied to the plurality of power storage cells 11 from the outside of the power storage device 1. At this time, when the switch 132 is turned on, a part of the current supplied to the storage cell 11 flows through the electric circuit 13. In the storage cell 11 in which a current flows through the connected electric circuit 13, a part of the supplied electric amount is consumed, and the amount of electricity stored by charging is larger than that in the storage cell 11 in which the current does not flow in the connected electric circuit 13. The amount of increase becomes smaller. That is, the amount of electricity corresponding to the difference in the amount of electricity stored is consumed, and the difference in the amount of electricity stored becomes smaller.

For each storage cell 11, the calculation unit 121 compares the time when the current is passed through the electric circuit 13 measured by the clock unit 127 and the discharge time recorded in the time data stored in the storage unit 123. The calculation unit 121 determines whether or not there is a storage cell 11 whose cumulative time for passing a current through the electric circuit 13 has reached the discharge time (S32). If there is no storage cell 11 whose cumulative time has reached the discharge time (S32: NO), the calculation unit 121 determines whether or not there is a storage cell 11 whose voltage is equal to or lower than a specific voltage (S33). .. For example, a specific voltage is stored in the storage unit 123 in advance, the BMU 12 acquires the voltage across each storage cell 11 by the voltage acquisition unit 124, and the calculation unit 121 acquires the acquired voltage and the specific voltage. Compare. The specific voltage is a voltage corresponding to the amount of electricity stored to be maintained by the electricity storage cell 11. For example, the value of a particular voltage is a predetermined value. For example, the specific voltage is the voltage corresponding to the smallest OCV among the OCVs of the plurality of storage cells 11 obtained in S22. The processing of S33 prevents the storage amount of the storage cell 11 from being excessively reduced, and the storage amount of the storage cell 11 is maintained at a certain amount.

When there is a storage cell 11 whose cumulative time has reached the discharge time (S32: YES), or when there is a storage cell 11 whose voltage is equal to or lower than a specific voltage (S33: YES), the calculation unit 121 corresponds. The adjustment of the storage amount of the storage cell 11 to be performed is completed (S34). In S34, the calculation unit 121 turns off the switch 132 included in the electric circuit 13 connected to the corresponding storage cell 11 so that the current does not flow in the electric circuit 13. As a result, the adjustment of the stored amount of the corresponding storage cell 11 is completed.

After the end of S34, or when there is no storage cell 11 whose voltage has dropped below a specific voltage in S33 (S33: NO), does the calculation unit 121 end the process of adjusting the amount of electricity stored in the storage cell 11. It is determined whether or not (S35). In S35, the calculation unit 121 determines that the process of adjusting the storage amount is completed when the adjustment of the storage amount of all the storage cells 11 is completed in S34. If there is a storage cell 11 for which the adjustment of the storage amount has not been completed, the calculation unit 121 determines that the processing is not completed. Further, in the form in which the processing is performed under a specific condition, the calculation unit 121 determines that the processing is terminated when the specific condition is not satisfied. For example, in the BMU 12 that adjusts the storage amount of each storage cell 11 only when the power storage device 1 is charging, the calculation unit 121 adjusts the storage amount of the storage cell 11 when the charging is completed. Is determined to end.

If it is determined that the process of adjusting the charge amount of the electricity storage cell 11 is not completed (S35: NO), the calculation unit 121 returns the process to S32. Adjustment of the storage amount is continued for the storage cell 11 in which the cumulative time for passing the current through the electric circuit 13 has not reached the discharge time. If it is determined that the process of adjusting the stored amount of the storage cell 11 is completed (S35: YES), the calculation unit 121 ends the process of adjusting the stored amount of the storage cell 11.

In a mode in which the process of adjusting the amount of electricity stored in the electricity storage cell 11 is performed under specific conditions, the BMU 12 may repeat the processes of S31 to S35. The calculation unit 121 may execute the processes of S31 to S35 again when the specific condition is satisfied again after the process is terminated because the specific condition is no longer satisfied in S35. For example, in the BMU 12 that adjusts the storage amount of each storage cell 11 only when the power storage device 1 is charging, the calculation unit 121 re-executes the processes of S31 to S35 when charging is performed again. do. When the processing of S31 to S35 is executed again, the calculation unit 121 does not adjust the storage amount of the storage cell 11 for which the adjustment of the storage amount has been completed in the previous processing. Further, in S32, the calculation unit 121 determines whether or not there is a storage cell 11 whose accumulated time has reached the discharge time in addition to the accumulated time in the previous process. Alternatively, the BMU 12 may be in the form of executing the process in which S33 is omitted in S31 to S35.

As described in detail above, the difference in the amount of electricity stored in the plurality of energy storage cells 11 is specified, and the discharge time required to discharge the amount of electricity corresponding to the difference in the amount of electricity stored from each energy storage cell 11 is determined. The power storage device 1 adjusts the storage amount of the storage cell 11 by passing a current through an electric circuit 13 connected to each storage cell 11 so as to consume an amount of electricity corresponding to the difference in the storage amount during the discharge time. .. Since it is necessary to measure OCV until the discharge time is determined, it is performed in a no-current state. In the process of adjusting the amount of electricity stored in the electricity storage cell 11, a current may be passed through the electric circuit 13 so as to consume an amount of electricity corresponding to the difference in the amount of electricity stored during the discharge time. It can be executed in any state of time. That is, by temporarily determining the discharge time and then performing a process of adjusting the storage amount of the storage cell 11 according to the discharge time, the power storage device 1 can perform the storage cell even during discharging or charging. The amount of electricity stored in 11 can be adjusted.

Since the power storage device 1 can adjust the power storage amount of the power storage cell 11 even during discharging or charging, the power storage device 1 is attached to the aircraft 2 and stores electricity even in a state where discharge or charging may be performed. The amount can be adjusted. By adjusting the storage amount of the storage cell 11 not only in the no-current state but also during discharging or charging, the opportunity to adjust the storage amount increases, and the storage amount of the storage cell 11 can be adjusted in a short period of time. .. Since the storage amount of the storage cell 11 can be adjusted after the power storage device 1 is attached to the aircraft 2, the period during which the power storage device 1 is removed from the aircraft 2 is shortened. In the process of maintenance of the aircraft 2, the process performed after the power storage device 1 is attached can be performed earlier, and the period required for the maintenance of the aircraft 2 is shortened.

The BMU 12 does not use the current flowing through the electric circuit 13 to determine the end of the adjustment of the storage amount of the storage cell 11. Further, in order to determine the end of the adjustment of the stored amount of the storage cell 11, the BMU 12 makes a determination using the time when the current flows through the electric circuit 13 without using the values of the current and the voltage in S32. The current and voltage during charging or discharging of the storage cell 11 are affected by the internal resistance of the storage cell 11 and the like, and it is difficult to accurately determine the change in the storage amount from the current or voltage. By comparing the discharge time obtained from the OCV with the time when the current flows through the electric circuit 13, the BMU 12 makes it easier and more accurate than the case of using the current or the voltage to store the amount of electricity in the storage cell 11. The end of adjustment can be determined. In addition, it is possible to prevent the storage amount of the storage cell 11 from being excessively reduced due to an inaccurate determination using current or voltage.

As described above, the BMU 12 may perform a process of adjusting the amount of electricity stored in each electricity storage cell 11 only when the electricity storage device 1 is charging. At the time of charging, a part of the current supplied for charging flows to the electric circuit 13, so that the difference in the amount of electricity stored becomes small, but the amount of electricity stored in the electricity storage cell 11 does not decrease. Therefore, it is possible to prevent the storage amount of the storage cell 11 from being excessively reduced due to the adjustment of the storage amount.

In the first embodiment, a mode is shown in which the charging / discharging device 3 executes the processing of S11 to S12 for specifying the full storage amount of each storage cell 11 and the processing of S13 for charging the storage device 1. Alternatively, the processing of S11 to S12 and the processing of S13 may be executed by different devices. In the first embodiment, a mode is shown in which the processing of S11 to S13 and the processing of S21 to S27 are executed by the charging / discharging device 3. Alternatively, the processes S11 to S13 and the processes S21 to S27 may be executed by different devices. For example, the processes of S21 to S27 may be executed by a device different from the charging / discharging device 3.

<Embodiment 2>
In the second embodiment, the necessary processing is mainly executed by the BMU 12. The BMU 12 specifies the full charge amount of each storage cell 11 and executes the processes of S11 to S13 for charging each storage cell 11. In S11, the BMU 12 completely charges the plurality of storage cells 11 by supplying a current from the charging / discharging device 3, and then completely discharges the storage cells 11. The BMU 12 acquires the current flowing through the plurality of storage cells 11, calculates the amount of electricity discharged from the plurality of storage cells 11, and calculates the full storage amount of the storage cells 11 to specify the full storage amount. In S12, the BMU 12 stores the fully stored amount data in which the fully stored amount is recorded in the storage unit 123. In S13, a plurality of storage cells 11 are charged by supplying a current from the charging / discharging device 3.

Next, the BMU 12 executes the processes of S21 to S27 for setting the adjustment of the stored amount. In S21, the BMU 12 determines that the power storage device 1 is in a non-current state. In S22, the BMU 12 acquires the OCV of each storage cell 11 by the voltage acquisition unit 124. In S23, the calculation unit 121 calculates the SOC of each storage cell 11 based on the acquired OCV value. In S24, the calculation unit 121 sets the value of the full storage amount recorded in the full storage amount data stored in the storage unit 123 as the full storage amount of each storage cell 11, and multiplies the full storage amount by the SOC of each storage cell 11. Thereby, the storage amount of each storage cell 11 is calculated. In S25, the calculation unit 121 calculates the difference in the amount of electricity stored in each electricity storage cell 11 with respect to the minimum amount of electricity stored.

Alternatively, the calculation unit 121 calculates the minimum storage amount in S24, and in S25, each storage cell is based on the difference between the SOC of the storage cell 11 having the minimum storage amount and the SOC of another storage cell 11. The difference in the amount of electricity stored in 11 may be calculated. Alternatively, in S25, the calculation unit 121 calculates the storage amount difference of each storage cell 11 based on the difference between the OCV of the storage cell 11 having the minimum storage amount and the OCV of another storage cell 11. May be good.

In S26, the calculation unit 121 calculates the discharge time required to discharge the electric quantity corresponding to the storage amount difference from the storage cell 11 to the electric circuit 13. In S27, the calculation unit 121 stores the time data in which the discharge time calculated for each storage cell 11 is recorded in the storage unit 123. The BMU 12 may perform the processes of S21 to S27 in a state where the power storage device 1 is removed from the charging / discharging device 3. After the completion of S21 to S27, the BMU 12 executes the processes of S31 to S35 for adjusting the storage amount of the storage cell 11 as in the first embodiment.

As described in detail above, in the second embodiment, the BMU 12 performs a process of determining the discharge time for adjusting the storage amount of the storage cell 11 and a process of adjusting the storage amount of the storage cell 11 according to the discharge time. Execute. Also in the second embodiment, the power storage device 1 can adjust the power storage amount of the power storage cell 11 even during discharging or charging. By mainly executing the necessary processing in the BMU 12, the power storage device 1 can adjust the power storage amount of the power storage cell 11 almost independently.

In the second embodiment, the processing of S11 to S13 and the processing of S21 to S27 are executed by BMU12. Alternatively, the charging / discharging device 3 may execute the processing of S11 to S13, and the BMU 12 may execute the processing of S21 to S27. In the first and second embodiments, a mode for specifying the full charge amount of the storage cell 11 is shown. Alternatively, the power storage device 1 may have a form in which the initial value of the full storage amount is used without specifying the full storage amount of the storage cell 11. For example, the initial value of the full storage amount is stored in the storage unit 123 in advance. In the first and second embodiments, the plurality of storage cells 11 included in the power storage device 1 are directly connected to each other. Alternatively, the power storage device 1 may include a power storage cell 11 connected in parallel in a plurality of power storage cells 11.

The present invention is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the claims. That is, an embodiment obtained by combining technical means appropriately modified within the scope of the claims is also included in the technical scope of the present invention.

1 Power storage device 11 Power storage cell 12 BMU (Management Department)
13 Electric circuit 131 Load 132 Switch 2 Aircraft 3 Charging / discharging device 40 Recording medium 41 Computer program

Claims (10)

It is a method of adjusting the amount of electricity stored in a plurality of energy storage cells included in the energy storage device of an aircraft.
Obtain the OCV (Open Circuit Voltage) of each storage cell and
Based on the acquired OCV, the storage amount difference indicating the difference in the storage amount of each storage cell with respect to the minimum storage amount among the storage amounts of the plurality of storage cells is calculated for each storage cell.
The discharge time required for discharging the amount of electricity corresponding to the difference in the amount of electricity stored from each electricity storage cell to the electric circuit connected to each electricity storage cell was calculated for each electricity storage cell.
The amount of electricity stored in each energy storage cell is adjusted by passing a current through the electric circuit connected to each energy storage cell so as to consume the amount of electricity corresponding to the difference in the amount of electricity stored.
When the cumulative time when the current flows through the electric circuit connected to the arbitrary storage cell reaches the discharge time calculated for the arbitrary storage cell, the adjustment of the storage amount of the arbitrary storage cell is completed. How to adjust the amount of electricity stored. The storage amount adjusting method according to claim 1, wherein the storage amount of each storage cell is adjusted when the plurality of storage cells are charged or discharged. A claim for adjusting the amount of electricity stored in each energy storage cell by passing a part of the current supplied to each energy storage cell for charging to the electric circuit connected to each energy storage cell at the time of charging the plurality of energy storage cells. Item 2. The method for adjusting the amount of electricity stored according to Item 1 or 2. Claim 1 to adjust the storage amount of each storage cell by flowing a part of the current supplied from each storage cell by the discharge to the electric circuit connected to each storage cell at the time of discharging the plurality of storage cells. The method for adjusting the amount of electricity stored according to any one of 3 to 3. The method for adjusting the amount of electricity stored according to any one of claims 1 to 4, wherein the electricity storage device is attached to the aircraft and the amount of electricity stored in each electricity storage cell is adjusted. A process for specifying the full charge amount, which represents the amount of electricity charged to the storage cell at the time of full charge, is performed.
Based on the OCV of each storage cell and the full storage amount, the minimum storage amount among the storage amounts of the plurality of storage cells is calculated.
The storage amount adjusting method according to any one of claims 1 to 5, wherein the storage amount difference is calculated for each storage cell based on the OCV of each storage cell and the minimum storage amount. When adjusting the storage capacity of each storage cell, measure the voltage of each storage cell and
The storage amount adjusting method according to any one of claims 1 to 6, wherein the adjustment of the storage amount of the arbitrary storage cell is terminated when the voltage of the arbitrary storage cell becomes equal to or lower than a specific voltage. A power storage device used in aircraft
With multiple storage cells
An electric circuit that is connected to each storage cell and consumes electricity by passing an electric current,
Equipped with a management department
The management department
The amount of electricity corresponding to the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells is stored in each electric circuit connected to each storage cell. The discharge time required to discharge from the cell is stored for each storage cell,
The amount of electricity stored in each energy storage cell is adjusted by passing a current through the electric circuit connected to each energy storage cell so as to consume the amount of electricity corresponding to the difference in the amount of electricity stored.
When the cumulative time when the current flows through the electric circuit connected to the arbitrary storage cell reaches the discharge time calculated for the arbitrary storage cell, the adjustment of the storage amount of the arbitrary storage cell is completed. Power storage device. The management department
When fully charged, the fully stored amount representing the amount of electricity charged in the storage cell is stored.
Acquire the OCV of each storage cell and
Based on the OCV of each storage cell and the full storage amount, the minimum storage amount among the storage amounts of the plurality of storage cells is calculated.
Based on the OCV of each storage cell and the minimum storage amount, the storage amount difference is calculated for each storage cell.
The power storage device according to claim 8, wherein the discharge time for each storage cell is calculated based on the storage amount difference. It is a computer program that causes a computer to adjust the amount of electricity stored in a plurality of energy storage cells included in the energy storage device of an aircraft.
An electric circuit connected to each storage cell so as to consume an amount of electricity corresponding to the difference in the amount of electricity stored, which indicates the difference in the amount of electricity stored in each storage cell with respect to the minimum amount of electricity stored in the plurality of storage cells. By passing an electric current, the amount of electricity stored in each energy storage cell is adjusted.
The cumulative amount of time that the current flows through the electric circuit connected to the arbitrary storage cell discharges the amount of electricity corresponding to the difference in the storage amount of the arbitrary storage cell from the arbitrary storage cell to the electric circuit. A computer program that causes a computer to execute a process of ending the adjustment of the amount of electricity stored in any storage cell when the discharge time required for the operation is reached.

Images