WO2021132421A1 - Electrical power device and control method for same - Google Patents

Electrical power device and control method for same Download PDF

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Publication number
WO2021132421A1
WO2021132421A1 PCT/JP2020/048336 JP2020048336W WO2021132421A1 WO 2021132421 A1 WO2021132421 A1 WO 2021132421A1 JP 2020048336 W JP2020048336 W JP 2020048336W WO 2021132421 A1 WO2021132421 A1 WO 2021132421A1
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WO
WIPO (PCT)
Prior art keywords
power storage
storage unit
storage units
voltage value
voltage
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PCT/JP2020/048336
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French (fr)
Japanese (ja)
Inventor
二川秀史
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本田技研工業株式会社
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Priority to JP2021567588A priority Critical patent/JPWO2021132421A1/ja
Publication of WO2021132421A1 publication Critical patent/WO2021132421A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L50/00—Electric propulsion with power supplied within the vehicle
    • B60L50/50—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells
    • B60L50/60—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells using power supplied by batteries
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/12—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries responding to state of charge [SoC]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/02—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/16—Information or communication technologies improving the operation of electric vehicles

Definitions

  • the present invention relates to a power device having at least three power storage units and a control method thereof.
  • a power device in which a plurality of batteries (storage units) are connected in parallel to each other via a voltage converter is disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-25791.
  • the voltage or SOC of the plurality of power storage units is proportional to the voltage difference of each power storage unit so as to be equal to each other. Charging and discharging is performed so that the current flows.
  • a plurality of power storage units are simply connected, there is no problem even if the power storage units are directly connected in parallel as long as the voltage difference is negligibly small.
  • a removable battery storage unit
  • the battery states such as voltage, temperature, internal resistance, SOC, degree of deterioration, and rechargeable capacity are different from each other
  • a plurality of batteries are connected in parallel after the battery is replaced.
  • a large voltage difference is generated between the power storage units, a large current (overcurrent) exceeding the allowable current due to the voltage difference flows.
  • a plurality of power storage units are connected in parallel via a equalization circuit, and the equalization circuit is electrically controlled to obtain a voltage between the plurality of power storage units. It is conceivable to reduce the difference. However, adding such an equalization circuit is costly.
  • the present invention has been made in consideration of such a problem, and is affected by cost by connecting a power storage unit only by electrical control and suppressing the occurrence of overcurrent without adding a circuit. It is an object of the present invention to provide an electric power device and a control method thereof which can minimize the above.
  • the first aspect of the present invention is a power device having at least three power storage units, the voltage acquisition unit for acquiring the voltage value of the power storage unit and the voltage value of the power storage unit acquired by the voltage acquisition unit. Based on the above, among the power storage units, the power storage unit has a connection unit for connecting two power storage units having adjacent voltage values to each other.
  • a second aspect of the present invention is a method for controlling a power device having at least three power storage units, in which a step of acquiring a voltage value of the power storage unit by a voltage acquisition unit and a step of acquiring the voltage value of the power storage unit are obtained. Based on the voltage value of the power storage unit, the power storage unit has a step of connecting two power storage units having adjacent voltage values to each other.
  • two power storage units having adjacent voltage values are selected from at least three power storage units and connected to each other.
  • the power storage unit can be connected only by electrical control without adding a circuit, and the occurrence of overcurrent can be suppressed.
  • the cost impact can be minimized. Therefore, as compared with the case where all the power storage units are connected at the same time or when two or more power storage units whose voltage values are separated from each other (not adjacent to each other) are connected, the power storage unit is reduced in voltage difference. It is possible to suppress the flow of overcurrent.
  • the electric power device 10 includes at least three power storage units 12, an ECU 14 (voltage acquisition unit, connection unit), a notification unit 16, and a built-in battery 18 (other power storage units). And a plurality of switches 20, 22.
  • FIG. 1 illustrates a case where four power storage units 12 (hereinafter, may be referred to as first to fourth power storage units 12a to 12d) are arranged.
  • the electric power device 10 is applied to a power supply system of various electric vehicles such as a one-wheeled vehicle, a two-wheeled vehicle, a three-wheeled vehicle, and a four-wheeled vehicle.
  • the electric power device 10 is not limited to the application to the electric vehicle.
  • Moving objects such as aircraft and ships other than vehicles, (2)
  • Various charging equipment such as household chargers, (3)
  • Various dischargers that output electric power from the power storage unit 12, (4) General-purpose work
  • various work machines such as machines, lawn mowers, tillers, and (5) power supply systems (Energy Storage System) that supply power to various electric devices installed or placed inside and outside buildings such as houses.
  • the power device 10 can be applied. In the following description, a case where the electric power device 10 is applied to the electric vehicle will be mainly described.
  • Each power storage unit 12 is a power storage device that can be attached to and detached from the power device 10 and can be charged and discharged.
  • a battery pack of a detachable lithium ion battery is suitable as the power storage unit 12.
  • Each power storage unit 12 is connected in parallel to a load 24 such as a motor of an electric vehicle and a PDU. That is, the positive electrode terminal on the output side of each power storage unit 12 is connected to the positive electrode terminal of the load 24. The negative electrode terminal on the output side of each power storage unit 12 is connected to the negative electrode terminal of the load 24.
  • the built-in battery 18 is a fixed power storage device provided in the power device 10.
  • the built-in battery 18 is connected in parallel to the load 24 via the switch 20. That is, the positive electrode terminal of the built-in battery 18 is connected to the positive electrode terminal of the load 24 via the switch 20.
  • the negative electrode terminal of the built-in battery 18 is connected to the negative electrode terminal of the load 24.
  • a voltage conversion circuit (not shown) such as a DC / DC converter may be inserted between the built-in battery 18 and the load 24.
  • the built-in battery 18 is not only a main power source for the electric power device 10, but also a start-up power source for activating each power storage unit 12. Therefore, the built-in battery 18 is also connected to each power storage unit 12 via each switch 22. That is, the positive electrode terminal of the built-in battery 18 is connected to the power supply terminal of the positive electrode of each power storage unit 12 via each switch 22. The negative electrode terminal of the built-in battery 18 is connected to the power supply terminal of the negative electrode of each power storage unit 12.
  • the ECU 14 is an electronic control device for an electric vehicle, and by reading and executing a program stored in a non-transient storage medium (not shown), connection control for each switch 26 (see FIG. 2) described later can be performed. Realize various functions. Further, the notification unit 16 is an output device such as a display device or a speaker provided in the electric vehicle, and notifies the processing result of the ECU 14 to the outside.
  • the ECU 14 and each power storage unit 12, each switch 20, 22 and the load 24 can transmit and receive signals or information via the communication line 28 of the Controller Area Network (CAN). Therefore, the ECU 14 controls and turns on the switches 20 and 22 to electrically connect the built-in battery 18 and the load 24, or electrically connect the built-in battery 18 and each power storage unit 12. ..
  • CAN Controller Area Network
  • FIG. 2 is an internal configuration diagram of each power storage unit 12.
  • Each power storage unit 12 has the same configuration, and in FIG. 2, only one power storage unit 12 is shown.
  • each power storage unit 12 includes a switch 26 (two-way connection circuit), a battery 30, a battery management system (BMU) 32, a resistor 34, a temperature sensor 36, and a communication unit 38. It is a battery pack that houses.
  • BMU battery management system
  • the positive electrode of the battery 30 is connected to the positive electrode terminal of the load 24 via the positive electrode terminal of the switch 26 and the power storage unit 12.
  • the negative electrode of the battery 30 is connected to the negative electrode terminal of the load 24 via the negative electrode terminal of the resistor 34 and the power storage unit 12.
  • the communication unit 38 transmits / receives a signal or information to / from the ECU 14 via the communication line 28.
  • the BMU 32 is activated by turning on the switch 22 under the control of the ECU 14 and supplying electric power from the built-in battery 18.
  • the BMU 32 monitors the battery 30 and the like. Specifically, the BMU 32 electrically connects the battery 30 and the load 24 by turning on the switch 26 based on the control signal received from the ECU 14 to the communication unit 38 via the communication line 28. Further, the BMU 32 sequentially detects the voltage values across the resistor 34, and sequentially determines the current value of the current (discharge current or charge current) flowing through the battery 30 based on the detected voltage value and the resistance value of the resistor 34. calculate.
  • the BMU 32 sequentially detects the voltage value of the battery 30, and sequentially calculates the SOC of the battery 30 based on the detected voltage value and the calculated current value. Furthermore, the BMU 32 sequentially acquires the temperature of the battery 30 detected by the temperature sensor 36 such as a thermistor. The BMU 32 sequentially transmits information including a voltage value, a current value, an SOC, and a temperature from the communication unit 38 to the ECU 14 via the communication line 28.
  • the ECU 14 sequentially acquires the above information, and determines (determines) whether or not each switch 26 needs to be turned on (connected) or turned off (disconnected) based on the acquired information. Further, the ECU 14 transmits a control signal based on the determination result to each communication unit 38 via the communication line 28 to turn on or off the switch 26 of each power storage unit 12. Further, the ECU 14 turns on or off the switches 20 and 22 by transmitting a control signal to the switches 20 and 22 via the communication line 28.
  • step S1 the ECU 14 switches each switch 22 from off to on by supplying a control signal to each switch 22.
  • the built-in battery 18 and the BMU 32 of each power storage unit 12 are electrically connected, and power supply from the built-in battery 18 to each power storage unit 12 (BMU 32) is started.
  • each BMU 32 is activated.
  • each communication unit 38 reaches a state in which it can communicate with the ECU 14 via the communication line 28 (step S1: YES).
  • step S1 the ECU 14 and each power storage unit 12 may perform a numbering process for assigning an ID number or the like to each power storage unit 12 via the communication line 28.
  • step S2 the BMU 32 of each power storage unit 12 detects the voltage value of the battery 30. In this case, each BMU 32 also acquires the temperature of the battery 30, calculates the current value of the current flowing through the battery 30, and calculates the SOC of the battery 30. Therefore, each BMU 32 transmits these information from the communication unit 38 to the ECU 14 via the communication line 28. Therefore, the ECU 14 can acquire information such as the voltage value of the battery 30 from each power storage unit 12.
  • step S3 the ECU 14 compares the voltage values of the batteries 30 of each power storage unit 12, and the voltage difference between the highest voltage value (maximum voltage value) and the lowest voltage value (minimum voltage value) is within the voltage threshold value. Determine if it exists.
  • the voltage threshold value is a threshold value for determining whether or not a large current (overcurrent) flowing between the power storage units 12 is generated due to the voltage difference, and is a voltage difference according to the allowable current. The value of. Therefore, if the voltage difference is within the voltage threshold value, the occurrence of overcurrent is suppressed. On the other hand, if the voltage difference exceeds the voltage threshold, overcurrent may occur.
  • step S4 the ECU 14 arranges all the power storage units 12 in parallel with the load 24. It is determined that no overcurrent occurs even if the connection is made. Next, based on this determination result, the ECU 14 transmits a control signal instructing the switch 26 to be turned on to the communication unit 38 of each power storage unit 12 via the communication line 28.
  • each power storage unit 12 switches the switch 26 from off to on based on the control signal received by the communication unit 38.
  • each power storage unit 12 (battery 30) is connected in parallel to the load 24.
  • the voltage value of the battery 30 of each power storage unit 12 can be averaged.
  • step S3 when the voltage difference between the maximum voltage value and the minimum voltage value exceeds the voltage threshold value (step S3: NO), the ECU 14 may generate an overcurrent when all the power storage units 12 are connected. It is determined that there is, and the process proceeds to step S5.
  • step S5 the ECU 14 compares the voltage values of the batteries 30 of each power storage unit 12 and selects a combination of connections of at least two power storage units 12 such that the voltage difference is within the voltage threshold value. That is, in the case of the selected combination of connections, since the voltage values are close to each other (adjacent to each other), it is considered that overcurrent does not occur if at least two storage units 12 are connected in parallel.
  • the ECU 14 transmits a control signal instructing the on of the switch 26 to the communication units 38 of at least two power storage units 12 via the communication line 28.
  • the BMU 32 of at least two power storage units 12 switches the switch 26 from off to on based on the control signal received by the communication unit 38.
  • at least two power storage units 12 (batteries 30) are connected in parallel to the load 24. As a result, it is possible to supply power to the load 24 and charge / discharge between the two power storage units 12 while suppressing the voltage difference between the two power storage units 12 within the voltage threshold value.
  • the BMU 32 sequentially acquires the voltage value and the like of each battery 30. Therefore, in the next step S6, the ECU 14 acquires information such as the voltage value of the battery 30 from at least two storage units 12, and from the voltage value included in the acquired information, between at least two storage units 12. It is determined whether or not the voltage value of the battery 30 is averaged by charging / discharging.
  • step S6 When the voltage value of the battery 30 is averaged (step S6: YES), the ECU 14 returns to step S2 and repeatedly executes the processes of steps S2, S3, S5, and S6. Therefore, in the power device 10 according to the present embodiment, until the voltage difference between the maximum voltage value and the minimum voltage value is within the voltage threshold value (step S3: YES), the ECU 14 is the voltage value of the battery 30 of each power storage unit 12. , The process of determining the connection of each power storage unit 12, and the process of connecting each power storage unit 12 by each switch 26 are repeatedly performed. That is, in the present embodiment, the power storage units 12 are connected in parallel in stages, and charging / discharging is performed between the power storage units 12 to average the voltage difference of each power storage unit 12.
  • the maximum voltage value is the first. 1
  • the case where all the storage units 12a to 12d are finally connected in parallel by repeating the parallel connection to the load 24 stepwise with reference to the power storage unit 12a is illustrated.
  • the second embodiment as shown in FIGS. 9 to 13, by repeating the parallel connection to the load 24 stepwise based on the fourth storage unit 12d having the minimum voltage value, all the storage is finally performed. The case where the parts 12a to 12d are connected in parallel is illustrated.
  • the voltage values before the connection of the first to fourth power storage units 12a to 12d are V1 to V4, and the voltage threshold value is set. Let it be Vthr. Further, in FIGS. 4 to 13, the first to fourth power storage units 12a to 12d are designated as No. 1 to No. It is written as 4.
  • the connection of the first to third storage units 12a to 12c, the connection of the second to fourth storage units 12b to 12d, the connection between the first storage unit 12a and the second storage unit 12b, the connection of the second storage unit 12b and the second In the connection with the 3 power storage unit 12c and the connection between the 3rd power storage unit 12c and the 4th power storage unit 12d, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other), so that the voltage difference is voltage. It is within the threshold voltage Vthr, and no overcurrent occurs (“OK” connection in FIG. 4).
  • the ECU 14 connects (connection A) between the first storage unit 12a and the second storage unit 12b with reference to the first storage unit 12a having the maximum voltage value (voltage value V1), or
  • connection (connection B) of the first to third power storage units 12a to 12c is selectively selected.
  • the ECU 14 when the ECU 14 selects the connection A, the ECU 14 transmits a control signal for turning on the switch 26 to the communication unit 38 of the first power storage unit 12a and the second power storage unit 12b via the communication line 28. To do. As a result, the BMU 32 of the first power storage unit 12a and the second power storage unit 12b switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the first power storage unit 12a and the second power storage unit 12b are connected in parallel to the load 24, and charging / discharging is performed between the first power storage unit 12a and the second power storage unit 12b (step of FIG. 3). S5).
  • the voltage value of the first storage unit 12a decreases from V1 to V12, while the voltage value of the second storage unit 12b increases from V2 to V12. That is, the voltage values of the first power storage unit 12a and the second power storage unit 12b are averaged to V12 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V1 to V12.
  • step S3 NO in FIG. 3
  • > Vthr is still obtained (step S3: NO in FIG. 3)
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, Overcurrent may flow (“NG” connection in FIG. 5).
  • the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other). ) Therefore, the voltage difference is within the voltage threshold Vthr, and no overcurrent occurs (“OK” connection in FIG. 5).
  • the ECU 14 selects the connection of the first to third storage units 12a to 12c with reference to the first storage unit 12a and the second storage unit 12b having the maximum voltage value (voltage value V12). Select.
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to third power storage units 12a to 12c via the communication line 28.
  • the BMUs 32 of the first to third storage units 12a to 12c turn on the switch 26 based on the control signal received by the communication unit 38.
  • the first to third power storage units 12a to 12c are connected in parallel to the load 24, and charging / discharging is performed between the first to third power storage units 12a to 12c (step S5 in FIG. 3).
  • the voltage values of the first power storage unit 12a and the second power storage unit 12b decreased from V12 to V123, while the voltage values of the third power storage unit 12c decreased from V3 to V123. Ascend to. That is, the voltage values of the first to third storage units 12a to 12c are averaged to V123 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V12 to V123.
  • step S3 YES in FIG. 3
  • the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the first to third storage units 12a to 12c having the maximum voltage value (voltage value V123).
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28.
  • the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38.
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
  • the voltage values of the first to third storage units 12a to 12c decreased from V123 to V1234, while the voltage values of the fourth storage unit 12d changed from V4 to V1234. To rise. That is, the voltage values of the first to fourth storage units 12a to 12d are averaged to V1234.
  • connection A in FIG. 4 is selectively selected.
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to third storage units 12a to 12c via the communication line 28. Send.
  • the BMUs 32 of the first to third storage units 12a to 12c switch the switch 26 from off to on based on the control signal received by the communication unit 38.
  • the first to third power storage units 12a to 12c are connected in parallel to the load 24, and charging / discharging is performed between the first to third power storage units 12a to 12c (step S5 in FIG. 3).
  • the voltage value of unit 12c rises from V3 to V123. That is, the voltage values of the first to third storage units 12a to 12c are averaged to V123 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V1 to V123.
  • step S3 YES in FIG. 3
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24 as in the case of FIG. However, no overcurrent occurs (“OK” connection in FIG. 8). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the first to third storage units 12a to 12c having the maximum voltage value (voltage value V123). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28.
  • the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38.
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
  • the voltage values of the first to third storage units 12a to 12c decrease from V123 to V1234, while the voltage values of the fourth storage units 12d are increased. It rises from V4 to V1234.
  • the connection B is selected, the voltage values of the first to fourth power storage units 12a to 12d can be quickly averaged to V1234 as compared with the case of the connection A.
  • connection of the first to third storage units 12a to 12c, the connection of the second to fourth storage units 12b to 12d, the connection between the first storage unit 12a and the second storage unit 12b, the connection of the second storage unit 12b and the second In the connection with the 3 power storage unit 12c and the connection between the 3rd power storage unit 12c and the 4th power storage unit 12d, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other), and the voltage difference is within the voltage threshold Vthr. Therefore, no overcurrent is generated (“OK” connection in FIG. 9).
  • the ECU 14 connects (connection C) between the third storage unit 12c and the fourth storage unit 12d with reference to the fourth storage unit 12d having the minimum voltage value (voltage value V4).
  • the connection (connection D) of the second to fourth power storage units 12b to 12d is selectively selected.
  • the ECU 14 when the ECU 14 selects the connection C, the ECU 14 transmits a control signal for turning on the switch 26 to the communication unit 38 of the third storage unit 12c and the fourth storage unit 12d via the communication line 28. To do. As a result, the BMU 32 of the third power storage unit 12c and the fourth power storage unit 12d switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the third power storage unit 12c and the fourth power storage unit 12d are connected in parallel to the load 24, and charging / discharging is performed between the third power storage unit 12c and the fourth power storage unit 12d (step of FIG. 3). S5).
  • the voltage value of the third storage unit 12c decreases from V3 to V34, while the voltage value of the fourth storage unit 12d increases from V4 to V34. That is, the voltage values of the third power storage unit 12c and the fourth power storage unit 12d are averaged to V34 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V4 to V34.
  • step S3 NO in FIG. 3
  • > Vthr step S3: NO in FIG. 3
  • the first to fourth storage units 12a to 12d are connected in parallel to the load 24, an overcurrent may flow. There is (“NG” connection in FIG. 10).
  • the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other). Since the voltage difference is within the voltage threshold Vthr, no overcurrent occurs (“OK” connection in FIG. 10).
  • the ECU 14 selectively selects the connection of the second to fourth storage units 12b to 12d based on the third storage unit 12c and the fourth storage unit 12d having the minimum voltage value (voltage value V34).
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the second to fourth power storage units 12b to 12d via the communication line 28.
  • the BMUs 32 of the second to fourth storage units 12b to 12d turn on the switch 26 based on the control signal received by the communication unit 38.
  • the second to fourth power storage units 12b to 12d are connected in parallel to the load 24, and charging and discharging are performed between the second to fourth power storage units 12b to 12d (step S5 in FIG. 3).
  • the voltage value of the second power storage unit 12b drops from V2 to V234, while the voltage values of the third power storage unit 12c and the fourth power storage unit 12d decrease from V34 to V234. Ascend to. That is, the voltage values of the second to fourth storage units 12b to 12d are averaged to V234 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V34 to V234.
  • step S3 YES in FIG. 3
  • the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the second to fourth storage units 12b to 12d having the minimum voltage value (voltage value V234).
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28.
  • the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38.
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
  • the voltage value of the first power storage unit 12a drops from V1 to V1234, while the voltage values of the second to fourth power storage units 12b to 12d change from V234 to V1234. To rise. That is, the voltage values of the first to fourth storage units 12a to 12d are averaged to V1234.
  • connection C in FIG. 9 is selectively selected.
  • the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the second to fourth power storage units 12b to 12d via the communication line 28. Send.
  • the BMUs 32 of the second to fourth storage units 12b to 12d switch the switch 26 from off to on based on the control signal received by the communication unit 38.
  • the second to fourth power storage units 12b to 12d are connected in parallel to the load 24, and charging and discharging are performed between the second to fourth power storage units 12b to 12d (step S5 in FIG. 3).
  • the voltage value of unit 12d rises from V4 to V234. That is, the voltage values of the second to fourth storage units 12b to 12d are averaged to V234 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V4 to V234.
  • step S3 YES in FIG. 3
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24 as in the case of FIG. However, no overcurrent is generated (“OK” connection in FIG. 13). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the second to fourth storage units 12b to 12d having the minimum voltage value (voltage value V234). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28.
  • the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38.
  • the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
  • the voltage value of the first power storage unit 12a drops from V1 to V1234 as shown in FIG. 12, while the voltage values of the second to fourth power storage units 12b to 12d are increased. It rises from V234 to V1234.
  • the connection D is selected, the voltage values of the first to fourth storage units 12a to 12d can be quickly averaged to V1234 as compared with the case of the connection C.
  • the electric power device 10 may have a configuration of a modified example shown in FIG.
  • each power storage unit 12 (12a to 12d) has only the battery 30 and the temperature sensor 36.
  • a voltage sensor 40 that sequentially detects the voltage value of the battery 30 is connected in parallel to each battery 30.
  • the positive electrode terminal of each battery 30 is connected to the positive electrode terminal of the load 24 via the current sensor 42 and the switch 26.
  • the negative electrode terminal of each battery 30 is connected to the negative electrode terminal of the load 24.
  • the current sensor 42 sequentially detects the current value of the current flowing through the battery 30.
  • the ECU 14 is connected to each temperature sensor 36, each voltage sensor 40, and each current sensor 42 via an analog signal line 44.
  • the ECU 14 sequentially acquires the temperature of the battery 30 detected by each temperature sensor 36, the voltage value of the battery 30 detected by each voltage sensor 40, and the current value detected by each current sensor 42. Therefore, even in this modification, the ECU 14 can execute the connection process of the switch 26 described above.
  • the ECU 14 acquires a voltage value or the like from each power storage unit 12. Further, in the configuration of FIG. 14, the ECU 14 inputs the voltage value detected by the voltage sensor 40 to the ECU 14. In the present embodiment, the ECU 14 may estimate the voltage value based on the information from each power storage unit 12, without being limited to these configurations.
  • the present embodiment relates to an electric power device 10 having at least three power storage units 12 (12a to 12d) and a control method thereof.
  • the electric power device 10 stores two electricity storage units 12 having adjacent voltage values based on the voltage acquisition unit that acquires the voltage value of the power storage unit 12 and the acquired voltage value of the power storage unit 12. It has an ECU 14 that functions as a connecting unit that connects the units 12 to each other.
  • the voltage value of the power storage unit 12 is determined based on the step (step S2) in which the ECU 14 acquires the voltage value of the power storage unit 12 and the acquired voltage value of the power storage unit 12. It has a step (steps S4 and S5) of connecting two adjacent power storage units 12 to each other.
  • two power storage units 12 having adjacent voltage values are selected from at least three power storage units 12 and connected to each other.
  • the power storage unit 12 can be connected only by electrical control without adding a circuit, and the occurrence of overcurrent can be suppressed.
  • the cost impact can be minimized. Therefore, as compared with the case where all the power storage units 12 are connected at the same time or when two or more power storage units 12 whose voltage values are separated from each other (not adjacent to each other) are connected, the voltage difference is reduced while reducing the voltage difference. It is possible to prevent an overcurrent from flowing through the power storage unit 12.
  • the ECU 14 has a power storage unit 12 having a maximum voltage value (for example, V1) having a maximum voltage value or a minimum voltage value (for example, V4) having a minimum voltage value, and the power storage unit 12 and a voltage value. Connects to the adjacent power storage unit 12 to each other. As a result, the two power storage units 12 are connected with reference to the power storage unit 12 having the maximum voltage value or the minimum voltage value. As a result, the maximum voltage value decreases or the minimum voltage value increases. Therefore, the overall voltage difference of each power storage unit 12 is surely reduced, and the occurrence of overcurrent can be efficiently suppressed.
  • V1 maximum voltage value
  • V4 minimum voltage value
  • the ECU 14 interconnects the power storage unit 12 having the maximum voltage value and the power storage unit 12 having the voltage value adjacent to the power storage unit 12.
  • the acquisition of the voltage value of the power storage unit 12 by the ECU 14 and the connection of the power storage unit 12 are repeatedly performed until the voltage difference between the maximum voltage value and the minimum voltage value is within a predetermined voltage threshold value.
  • a predetermined voltage threshold value it is possible to connect all the power storage units 12 and reliably average the voltage values while suppressing the occurrence of overcurrent.
  • the ECU 14 when the ECU 14 includes two power storage units 12 having substantially the same voltage value, the ECU 14 has three power storage units 12 including the two power storage units 12 and the two power storage units 12 and the power storage units 12 having voltage values adjacent to each other. To interconnect. As a result, the voltage values of each power storage unit 12 can be averaged quickly and efficiently.
  • a built-in battery 18 (another power storage unit) different from the three power storage units 12 is connected to the load 24 in parallel with the power storage unit 12. As a result, it is possible to supply electric power from the built-in battery 18 to the load 24 and to supply electric power from the built-in battery 18 to each power storage unit 12 to start each power storage unit 12.
  • the ECU 14 prohibits the connection of the two storage units 12 to each other. As a result, the occurrence of overcurrent can be reliably suppressed.
  • the electric power device 10 includes three switches 26 (two-way connection circuit) for connecting any two power storage units 12 to each other among the three power storage units 12.
  • the individual switches 26 can be electrically controlled from the ECU 14.
  • the ECU 14 can connect the power storage units 12 to each other by selecting one of the switches 26.

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Abstract

An electrical power device (10) and a control method for the electrical power device (10) wherein an ECU (14) acquires voltage values of at least three electrical storage units (12 (12a–12d)) and, on the basis of the acquired voltage values, mutually connects two electrical storage units (12), among the electrical storage units (12), that have adjacent voltage values.

Description

電力装置及びその制御方法Electric power device and its control method
　本発明は、少なくとも３つの蓄電部を有する電力装置及びその制御方法に関する。 The present invention relates to a power device having at least three power storage units and a control method thereof.
　複数のバッテリ（蓄電部）が電圧変換器を介して互いに並列接続される電力装置が、例えば、特開２０１６－２５７９１号公報に開示されている。 A power device in which a plurality of batteries (storage units) are connected in parallel to each other via a voltage converter is disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-25791.
　ところで、電圧又はＳＯＣ（充電率）が異なる複数の蓄電部を互いに並列接続する場合、複数の蓄電部の間では、電圧又はＳＯＣが互いに均等になるように、各蓄電部の電圧差に比例して電流が流れる充放電が行われる。この場合、複数の蓄電部を単純に結線した際、無視できるほど小さな電圧差であれば、各蓄電部を直接、並列接続しても問題はない。 By the way, when a plurality of power storage units having different voltages or SOCs (charge rates) are connected in parallel to each other, the voltage or SOC of the plurality of power storage units is proportional to the voltage difference of each power storage unit so as to be equal to each other. Charging and discharging is performed so that the current flows. In this case, when a plurality of power storage units are simply connected, there is no problem even if the power storage units are directly connected in parallel as long as the voltage difference is negligibly small.
　しかしながら、固定型電池ではない着脱式バッテリ（蓄電部）において、電圧、温度、内部抵抗、ＳＯＣ、劣化度、充電可能容量等のバッテリ状態が互いに異なる場合、バッテリ交換後、並列接続される複数の蓄電部の間で大きな電圧差が発生すると、当該電圧差に起因した許容電流を超える大電流（過電流）が流れる。 However, in a removable battery (storage unit) that is not a fixed battery, if the battery states such as voltage, temperature, internal resistance, SOC, degree of deterioration, and rechargeable capacity are different from each other, a plurality of batteries are connected in parallel after the battery is replaced. When a large voltage difference is generated between the power storage units, a large current (overcurrent) exceeding the allowable current due to the voltage difference flows.
　このような過電流の発生を抑制するためには、均等化回路を介して複数の蓄電部を並列接続し、該均等化回路を電気的に制御することで、複数の蓄電部の間の電圧差を小さくすることが考えられる。しかしながら、このような均等化回路を追加すれば、コストがかかる。 In order to suppress the occurrence of such an overcurrent, a plurality of power storage units are connected in parallel via a equalization circuit, and the equalization circuit is electrically controlled to obtain a voltage between the plurality of power storage units. It is conceivable to reduce the difference. However, adding such an equalization circuit is costly.
　本発明は、このような課題を考慮してなされたものであり、回路を追加することなく、電気的な制御のみで蓄電部を接続して過電流の発生を抑制することにより、コストの影響を最小限に抑えることができる電力装置及びその制御方法を提供することを目的とする。 The present invention has been made in consideration of such a problem, and is affected by cost by connecting a power storage unit only by electrical control and suppressing the occurrence of overcurrent without adding a circuit. It is an object of the present invention to provide an electric power device and a control method thereof which can minimize the above.
　本発明の第１の態様は、少なくとも３つの蓄電部を有する電力装置であって、前記蓄電部の電圧値をそれぞれ取得する電圧取得部と、前記電圧取得部が取得した前記蓄電部の電圧値に基づいて、前記蓄電部のうち、前記電圧値が隣接する２つの前記蓄電部を相互に接続する接続部とを有する。 The first aspect of the present invention is a power device having at least three power storage units, the voltage acquisition unit for acquiring the voltage value of the power storage unit and the voltage value of the power storage unit acquired by the voltage acquisition unit. Based on the above, among the power storage units, the power storage unit has a connection unit for connecting two power storage units having adjacent voltage values to each other.
　本発明の第２の態様は、少なくとも３つの蓄電部を有する電力装置の制御方法であって、電圧取得部によって前記蓄電部の電圧値をそれぞれ取得するステップと、前記電圧取得部が取得した前記蓄電部の電圧値に基づいて、前記蓄電部のうち、前記電圧値が隣接する２つの前記蓄電部を相互に接続するステップとを有する。 A second aspect of the present invention is a method for controlling a power device having at least three power storage units, in which a step of acquiring a voltage value of the power storage unit by a voltage acquisition unit and a step of acquiring the voltage value of the power storage unit are obtained. Based on the voltage value of the power storage unit, the power storage unit has a step of connecting two power storage units having adjacent voltage values to each other.
　本発明によれば、少なくとも３つの蓄電部の中から、電圧値が隣接する２つの蓄電部を選択して相互に接続する。これにより、回路を追加することなく、電気的な制御のみで蓄電部を接続し、過電流の発生を抑制することができる。この結果、コストの影響を最小限に抑えることができる。従って、全ての蓄電部を同時に接続する場合や、電圧値が互いに離れている（隣接していない）２つ以上の蓄電部を接続する場合と比較して、電圧差を低減しつつ、蓄電部に過電流が流れることを抑制することができる。 According to the present invention, two power storage units having adjacent voltage values are selected from at least three power storage units and connected to each other. As a result, the power storage unit can be connected only by electrical control without adding a circuit, and the occurrence of overcurrent can be suppressed. As a result, the cost impact can be minimized. Therefore, as compared with the case where all the power storage units are connected at the same time or when two or more power storage units whose voltage values are separated from each other (not adjacent to each other) are connected, the power storage unit is reduced in voltage difference. It is possible to suppress the flow of overcurrent.
本実施形態に係る電力装置の構成図である。It is a block diagram of the electric power apparatus which concerns on this embodiment. 図１の蓄電部の構成図である。It is a block diagram of the power storage part of FIG. 図１の電力装置の動作を図示したフローチャートである。It is a flowchart which illustrated the operation of the electric power apparatus of FIG. 第１実施例の説明図である。It is explanatory drawing of 1st Example. 第１実施例の説明図である。It is explanatory drawing of 1st Example. 第１実施例の説明図である。It is explanatory drawing of 1st Example. 第１実施例の説明図である。It is explanatory drawing of 1st Example. 第１実施例の他の接続例の説明図である。It is explanatory drawing of the other connection example of 1st Example. 第２実施例の説明図である。It is explanatory drawing of 2nd Example. 第２実施例の説明図である。It is explanatory drawing of 2nd Example. 第２実施例の説明図である。It is explanatory drawing of 2nd Example. 第２実施例の説明図である。It is explanatory drawing of 2nd Example. 第２実施例の他の接続例の説明図である。It is explanatory drawing of another connection example of 2nd Example. 変形例に係る電力装置の構成図である。It is a block diagram of the electric power apparatus which concerns on a modification.
　以下、本発明に係る電力装置及びその制御方法について好適な実施形態を例示し、添付の図面を参照しながら説明する。 Hereinafter, a suitable embodiment of the electric power device and its control method according to the present invention will be illustrated and described with reference to the attached drawings.
［１．本実施形態の概略構成］
　本実施形態に係る電力装置１０は、図１に示すように、少なくとも３つの蓄電部１２と、ＥＣＵ１４（電圧取得部、接続部）と、報知部１６と、内蔵バッテリ１８（他の蓄電部）と、複数のスイッチ２０、２２とを有する。なお、図１では、４つの蓄電部１２（以下、第１～第４蓄電部１２ａ～１２ｄという場合がある。）が配置される場合を図示している。 [1. Schematic configuration of this embodiment]
As shown in FIG. 1, the electric power device 10 according to the present embodiment includes at least three power storage units 12, an ECU 14 (voltage acquisition unit, connection unit), a notification unit 16, and a built-in battery 18 (other power storage units). And a plurality of switches 20, 22. Note that FIG. 1 illustrates a case where four power storage units 12 (hereinafter, may be referred to as first to fourth power storage units 12a to 12d) are arranged.
　また、電力装置１０は、例えば、一輪車、二輪車、三輪車、四輪車等の各種の電動車両の電源システムに適用される。なお、電力装置１０は、電動車両への適用に限定されることはない。（１）車両以外の航空機や船舶等の移動体、（２）家庭用の充電器等の各種の充電設備、（３）蓄電部１２から電力を出力させる各種の放電器、（４）汎用作業機、芝刈り機、耕うん機等の各種の作業機、（５）家屋等の建物の内外に設置又は配置されている各種の電気機器に電力を供給する電源システム（Ｅｎｅｒｇｙ　Ｓｔｏｒａｇｅ　Ｓｙｓｔｅｍ）にも、電力装置１０を適用可能である。以下の説明では、主として、電動車両に電力装置１０を適用した場合について説明する。 Further, the electric power device 10 is applied to a power supply system of various electric vehicles such as a one-wheeled vehicle, a two-wheeled vehicle, a three-wheeled vehicle, and a four-wheeled vehicle. The electric power device 10 is not limited to the application to the electric vehicle. (1) Moving objects such as aircraft and ships other than vehicles, (2) Various charging equipment such as household chargers, (3) Various dischargers that output electric power from the power storage unit 12, (4) General-purpose work For various work machines such as machines, lawn mowers, tillers, and (5) power supply systems (Energy Storage System) that supply power to various electric devices installed or placed inside and outside buildings such as houses. The power device 10 can be applied. In the following description, a case where the electric power device 10 is applied to the electric vehicle will be mainly described.
　各蓄電部１２は、電力装置１０に対して着脱可能で、且つ、充放電可能な蓄電装置である。例えば、着脱式のリチウムイオンバッテリのバッテリパックが蓄電部１２として好適である。各蓄電部１２は、電動車両のモータ及びＰＤＵ等の負荷２４に対して並列に接続されている。すなわち、各蓄電部１２の出力側の正極端子は、負荷２４の正極端子と接続されている。各蓄電部１２の出力側の負極端子は、負荷２４の負極端子と接続されている。 Each power storage unit 12 is a power storage device that can be attached to and detached from the power device 10 and can be charged and discharged. For example, a battery pack of a detachable lithium ion battery is suitable as the power storage unit 12. Each power storage unit 12 is connected in parallel to a load 24 such as a motor of an electric vehicle and a PDU. That is, the positive electrode terminal on the output side of each power storage unit 12 is connected to the positive electrode terminal of the load 24. The negative electrode terminal on the output side of each power storage unit 12 is connected to the negative electrode terminal of the load 24.
　内蔵バッテリ１８は、電力装置１０に設けられている固定型の蓄電装置である。内蔵バッテリ１８は、スイッチ２０を介して負荷２４に並列に接続されている。すなわち、内蔵バッテリ１８の正極端子は、スイッチ２０を介して、負荷２４の正極端子と接続されている。内蔵バッテリ１８の負極端子は、負荷２４の負極端子と接続されている。なお、内蔵バッテリ１８と負荷２４との間には、ＤＣ／ＤＣコンバータ等の不図示の電圧変換回路が介挿されてもよい。これにより、各蓄電部１２と内蔵バッテリ１８との双方から負荷２４に電力を供給する場合、内蔵バッテリ１８の電圧を電圧変換回路で調整し、調整後の電圧を負荷２４側に出力することができる。また、内蔵バッテリ１８単独で負荷２４に電力を供給するか、又は、各蓄電部１２から負荷２４に電力を供給する場合には、電圧変換回路は無くてもよい。 The built-in battery 18 is a fixed power storage device provided in the power device 10. The built-in battery 18 is connected in parallel to the load 24 via the switch 20. That is, the positive electrode terminal of the built-in battery 18 is connected to the positive electrode terminal of the load 24 via the switch 20. The negative electrode terminal of the built-in battery 18 is connected to the negative electrode terminal of the load 24. A voltage conversion circuit (not shown) such as a DC / DC converter may be inserted between the built-in battery 18 and the load 24. As a result, when power is supplied to the load 24 from both the power storage unit 12 and the built-in battery 18, the voltage of the built-in battery 18 can be adjusted by the voltage conversion circuit, and the adjusted voltage can be output to the load 24 side. it can. Further, when the built-in battery 18 alone supplies power to the load 24, or when power is supplied from each power storage unit 12 to the load 24, the voltage conversion circuit may not be provided.
　内蔵バッテリ１８は、電力装置１０の主電源であると共に、各蓄電部１２を起動させるための起動用電源でもある。従って、内蔵バッテリ１８は、各スイッチ２２を介して各蓄電部１２にも接続されている。すなわち、内蔵バッテリ１８の正極端子は、各スイッチ２２を介して、各蓄電部１２の正極の電源端子と接続されている。内蔵バッテリ１８の負極端子は、各蓄電部１２の負極の電源端子と接続されている。 The built-in battery 18 is not only a main power source for the electric power device 10, but also a start-up power source for activating each power storage unit 12. Therefore, the built-in battery 18 is also connected to each power storage unit 12 via each switch 22. That is, the positive electrode terminal of the built-in battery 18 is connected to the power supply terminal of the positive electrode of each power storage unit 12 via each switch 22. The negative electrode terminal of the built-in battery 18 is connected to the power supply terminal of the negative electrode of each power storage unit 12.
　ＥＣＵ１４は、電動車両の電子制御装置であり、不図示の非一過性の記憶媒体に記憶されたプログラムを読み出して実行することにより、後述する各スイッチ２６（図２参照）に対する接続制御等の各種機能を実現する。また、報知部１６は、電動車両に備わる表示装置又はスピーカ等の出力装置であり、ＥＣＵ１４の処理結果を外部に報知する。 The ECU 14 is an electronic control device for an electric vehicle, and by reading and executing a program stored in a non-transient storage medium (not shown), connection control for each switch 26 (see FIG. 2) described later can be performed. Realize various functions. Further, the notification unit 16 is an output device such as a display device or a speaker provided in the electric vehicle, and notifies the processing result of the ECU 14 to the outside.
　ＥＣＵ１４と、各蓄電部１２、各スイッチ２０、２２及び負荷２４とは、Ｃｏｎｔｒｏｌｌｅｒ　Ａｒｅａ　Ｎｅｔｗｏｒｋ（ＣＡＮ）の通信線２８を介して、信号又は情報の送受信が可能である。従って、ＥＣＵ１４は、各スイッチ２０、２２を制御してオンさせることで、内蔵バッテリ１８と負荷２４とを電気的に接続させ、又は、内蔵バッテリ１８と各蓄電部１２とを電気的に接続させる。 The ECU 14 and each power storage unit 12, each switch 20, 22 and the load 24 can transmit and receive signals or information via the communication line 28 of the Controller Area Network (CAN). Therefore, the ECU 14 controls and turns on the switches 20 and 22 to electrically connect the built-in battery 18 and the load 24, or electrically connect the built-in battery 18 and each power storage unit 12. ..
　図２は、各蓄電部１２の内部構成図である。各蓄電部１２は、同じ構成を有しており、図２では、１つの蓄電部１２のみ図示している。図２に示すように、各蓄電部１２は、スイッチ２６（二者接続回路）と、バッテリ３０と、バッテリマネジメントシステム（ＢＭＵ）３２と、抵抗器３４と、温度センサ３６と、通信部３８とを収容するバッテリパックである。 FIG. 2 is an internal configuration diagram of each power storage unit 12. Each power storage unit 12 has the same configuration, and in FIG. 2, only one power storage unit 12 is shown. As shown in FIG. 2, each power storage unit 12 includes a switch 26 (two-way connection circuit), a battery 30, a battery management system (BMU) 32, a resistor 34, a temperature sensor 36, and a communication unit 38. It is a battery pack that houses.
　バッテリ３０の正極は、スイッチ２６及び蓄電部１２の正極端子を介して負荷２４の正極端子に接続されている。バッテリ３０の負極は、抵抗器３４及び蓄電部１２の負極端子を介して負荷２４の負極端子に接続されている。また、通信部３８は、通信線２８を介してＥＣＵ１４との間で信号又は情報の送受信を行う。 The positive electrode of the battery 30 is connected to the positive electrode terminal of the load 24 via the positive electrode terminal of the switch 26 and the power storage unit 12. The negative electrode of the battery 30 is connected to the negative electrode terminal of the load 24 via the negative electrode terminal of the resistor 34 and the power storage unit 12. Further, the communication unit 38 transmits / receives a signal or information to / from the ECU 14 via the communication line 28.
　ＢＭＵ３２は、ＥＣＵ１４の制御でスイッチ２２がオンとなり、内蔵バッテリ１８から電力が供給されることで起動する。ＢＭＵ３２は、バッテリ３０の監視等を行う。具体的に、ＢＭＵ３２は、ＥＣＵ１４から通信線２８を介して通信部３８に受信される制御信号に基づき、スイッチ２６をオンさせることで、バッテリ３０と負荷２４とを電気的に接続する。また、ＢＭＵ３２は、抵抗器３４の両端の電圧値を逐次検出し、検出した電圧値と抵抗器３４の抵抗値とに基づき、バッテリ３０に流れる電流（放電電流又は充電電流）の電流値を逐次算出する。さらに、ＢＭＵ３２は、バッテリ３０の電圧値を逐次検出し、検出した電圧値と、算出した電流値とに基づき、バッテリ３０のＳＯＣを逐次算出する。さらにまた、ＢＭＵ３２は、サーミスタ等の温度センサ３６が検出したバッテリ３０の温度を逐次取得する。ＢＭＵ３２は、通信部３８から通信線２８を介してＥＣＵ１４に、電圧値、電流値、ＳＯＣ及び温度を含む情報を逐次送信する。 The BMU 32 is activated by turning on the switch 22 under the control of the ECU 14 and supplying electric power from the built-in battery 18. The BMU 32 monitors the battery 30 and the like. Specifically, the BMU 32 electrically connects the battery 30 and the load 24 by turning on the switch 26 based on the control signal received from the ECU 14 to the communication unit 38 via the communication line 28. Further, the BMU 32 sequentially detects the voltage values across the resistor 34, and sequentially determines the current value of the current (discharge current or charge current) flowing through the battery 30 based on the detected voltage value and the resistance value of the resistor 34. calculate. Further, the BMU 32 sequentially detects the voltage value of the battery 30, and sequentially calculates the SOC of the battery 30 based on the detected voltage value and the calculated current value. Furthermore, the BMU 32 sequentially acquires the temperature of the battery 30 detected by the temperature sensor 36 such as a thermistor. The BMU 32 sequentially transmits information including a voltage value, a current value, an SOC, and a temperature from the communication unit 38 to the ECU 14 via the communication line 28.
　従って、ＥＣＵ１４は、上記の情報を逐次取得し、取得した各情報に基づいて、各スイッチ２６のオン（接続）又はオフ（遮断）の要否を決定（判定）する。また、ＥＣＵ１４は、この判定結果に基づく制御信号を、通信線２８を介して各通信部３８に送信することで、各蓄電部１２のスイッチ２６をオン又はオフさせる。さらに、ＥＣＵ１４は、通信線２８を介して各スイッチ２０、２２に制御信号を送信することで、各スイッチ２０、２２をオン又はオフさせる。 Therefore, the ECU 14 sequentially acquires the above information, and determines (determines) whether or not each switch 26 needs to be turned on (connected) or turned off (disconnected) based on the acquired information. Further, the ECU 14 transmits a control signal based on the determination result to each communication unit 38 via the communication line 28 to turn on or off the switch 26 of each power storage unit 12. Further, the ECU 14 turns on or off the switches 20 and 22 by transmitting a control signal to the switches 20 and 22 via the communication line 28.
［２．本実施形態の動作］
　以上のように構成される本実施形態に係る電力装置１０の動作（電力装置１０の制御方法）について、図３を参照しながら説明する。この動作は、各蓄電部１２（図１及び図２参照）同士、又は、負荷２４に対する各蓄電部１２を段階的に並列接続して、各蓄電部１２の電圧差を電気的に制御することにより、許容電流を超える大電流（過電流）が各蓄電部１２間を含む電力装置１０内に流れることを回避するというものである。 [2. Operation of this embodiment]
The operation of the electric power device 10 (control method of the electric power device 10) according to the present embodiment configured as described above will be described with reference to FIG. In this operation, the power storage units 12 (see FIGS. 1 and 2) are connected to each other or the power storage units 12 with respect to the load 24 are connected in parallel in a stepwise manner, and the voltage difference between the power storage units 12 is electrically controlled. As a result, it is possible to prevent a large current (overcurrent) exceeding the permissible current from flowing into the electric power device 10 including between the storage units 12.
　この動作説明では、スイッチ２０のオフによって内蔵バッテリ１８と負荷２４との接続が遮断されている場合に、各蓄電部１２から負荷２４に電力を供給する場合について説明する。なお、スイッチ２０のオンによって内蔵バッテリ１８と負荷２４とを接続する場合には、内蔵バッテリ１８は、不図示の電圧変換回路を介して、負荷２４に電力を供給することに留意する。 In this operation description, a case where power is supplied from each power storage unit 12 to the load 24 when the connection between the built-in battery 18 and the load 24 is cut off by turning off the switch 20 will be described. When the built-in battery 18 and the load 24 are connected by turning on the switch 20, it should be noted that the built-in battery 18 supplies electric power to the load 24 via a voltage conversion circuit (not shown).
　ステップＳ１において、ＥＣＵ１４は、各スイッチ２２に制御信号を供給することで、各スイッチ２２をオフからオンに切り替える。これにより、内蔵バッテリ１８と各蓄電部１２のＢＭＵ３２とが電気的に接続され、該内蔵バッテリ１８から各蓄電部１２（ＢＭＵ３２）への電力供給が開始される。これにより、各ＢＭＵ３２が起動する。また、各通信部３８は、通信線２８を介してＥＣＵ１４と通信可能な状態に至る（ステップＳ１：ＹＥＳ）。なお、ステップＳ１において、ＥＣＵ１４及び各蓄電部１２は、通信線２８を介して、各蓄電部１２にＩＤ番号等を付与する付番処理を行ってもよい。 In step S1, the ECU 14 switches each switch 22 from off to on by supplying a control signal to each switch 22. As a result, the built-in battery 18 and the BMU 32 of each power storage unit 12 are electrically connected, and power supply from the built-in battery 18 to each power storage unit 12 (BMU 32) is started. As a result, each BMU 32 is activated. Further, each communication unit 38 reaches a state in which it can communicate with the ECU 14 via the communication line 28 (step S1: YES). In step S1, the ECU 14 and each power storage unit 12 may perform a numbering process for assigning an ID number or the like to each power storage unit 12 via the communication line 28.
　ステップＳ２において、各蓄電部１２のＢＭＵ３２は、バッテリ３０の電圧値を検出する。この場合、各ＢＭＵ３２は、バッテリ３０の温度の取得、バッテリ３０に流れる電流の電流値の算出、及び、バッテリ３０のＳＯＣの算出を併せて行っている。そのため、各ＢＭＵ３２は、これらの情報を、通信部３８から通信線２８を介してＥＣＵ１４に送信する。従って、ＥＣＵ１４は、各蓄電部１２からバッテリ３０の電圧値等の情報を取得することができる。 In step S2, the BMU 32 of each power storage unit 12 detects the voltage value of the battery 30. In this case, each BMU 32 also acquires the temperature of the battery 30, calculates the current value of the current flowing through the battery 30, and calculates the SOC of the battery 30. Therefore, each BMU 32 transmits these information from the communication unit 38 to the ECU 14 via the communication line 28. Therefore, the ECU 14 can acquire information such as the voltage value of the battery 30 from each power storage unit 12.
　ステップＳ３において、ＥＣＵ１４は、各蓄電部１２のバッテリ３０の電圧値を比較し、最も高い電圧値（最大電圧値）と、最も低い電圧値（最小電圧値）との電圧差が電圧閾値以内であるか否かを判定する。ここで、電圧閾値とは、電圧差に起因して各蓄電部１２の間を流れる大電流（過電流）が発生するか否かを判定するための閾値であり、許容電流に応じた電圧差の値をいう。従って、電圧差が電圧閾値以内に収まっていれば過電流の発生は抑制される。一方、電圧差が電圧閾値を超えていれば、過電流が発生する可能性がある。 In step S3, the ECU 14 compares the voltage values of the batteries 30 of each power storage unit 12, and the voltage difference between the highest voltage value (maximum voltage value) and the lowest voltage value (minimum voltage value) is within the voltage threshold value. Determine if it exists. Here, the voltage threshold value is a threshold value for determining whether or not a large current (overcurrent) flowing between the power storage units 12 is generated due to the voltage difference, and is a voltage difference according to the allowable current. The value of. Therefore, if the voltage difference is within the voltage threshold value, the occurrence of overcurrent is suppressed. On the other hand, if the voltage difference exceeds the voltage threshold, overcurrent may occur.
　ここで、最大電圧値と最小電圧値との電圧差が電圧閾値以内に収まっていれば（ステップＳ３：ＹＥＳ）、ステップＳ４において、ＥＣＵ１４は、負荷２４に対して全ての蓄電部１２を並列に接続しても過電流は発生しないと判定する。次に、ＥＣＵ１４は、この判定結果に基づき、通信線２８を介して各蓄電部１２の通信部３８に、スイッチ２６のオンを指示する制御信号を送信する。 Here, if the voltage difference between the maximum voltage value and the minimum voltage value is within the voltage threshold value (step S3: YES), in step S4, the ECU 14 arranges all the power storage units 12 in parallel with the load 24. It is determined that no overcurrent occurs even if the connection is made. Next, based on this determination result, the ECU 14 transmits a control signal instructing the switch 26 to be turned on to the communication unit 38 of each power storage unit 12 via the communication line 28.
　各蓄電部１２のＢＭＵ３２は、通信部３８で受信された制御信号に基づき、スイッチ２６をオフからオンに切り替える。これにより、負荷２４に対して各蓄電部１２（バッテリ３０）が並列に接続される。この結果、各蓄電部１２の間の電圧差を電圧閾値以内に抑えつつ、負荷２４への電力供給や、各蓄電部１２の間での充放電を行うことができる。これにより、各蓄電部１２のバッテリ３０の電圧値を平均化することができる。 The BMU 32 of each power storage unit 12 switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, each power storage unit 12 (battery 30) is connected in parallel to the load 24. As a result, it is possible to supply power to the load 24 and charge / discharge between the power storage units 12 while suppressing the voltage difference between the power storage units 12 within the voltage threshold value. Thereby, the voltage value of the battery 30 of each power storage unit 12 can be averaged.
　一方、ステップＳ３において、最大電圧値と最小電圧値との電圧差が電圧閾値を超えている場合（ステップＳ３：ＮＯ）、ＥＣＵ１４は、全ての蓄電部１２を接続すると過電流が発生する可能性があると判定し、ステップＳ５に進む。ステップＳ５において、ＥＣＵ１４は、各蓄電部１２のバッテリ３０の電圧値を比較し、電圧閾値以内の電圧差となるような少なくとも２つの蓄電部１２の接続の組み合わせを選択する。すなわち、選択した接続の組み合わせの場合、互いの電圧値が近い（隣接している）ため、少なくとも２つの蓄電部１２を並列に接続すれば、過電流は発生しないと考えられる。 On the other hand, in step S3, when the voltage difference between the maximum voltage value and the minimum voltage value exceeds the voltage threshold value (step S3: NO), the ECU 14 may generate an overcurrent when all the power storage units 12 are connected. It is determined that there is, and the process proceeds to step S5. In step S5, the ECU 14 compares the voltage values of the batteries 30 of each power storage unit 12 and selects a combination of connections of at least two power storage units 12 such that the voltage difference is within the voltage threshold value. That is, in the case of the selected combination of connections, since the voltage values are close to each other (adjacent to each other), it is considered that overcurrent does not occur if at least two storage units 12 are connected in parallel.
　次に、ＥＣＵ１４は、通信線２８を介して、少なくとも２つの蓄電部１２の通信部３８に、スイッチ２６のオンを指示する制御信号を送信する。これにより、少なくとも２つの蓄電部１２のＢＭＵ３２は、通信部３８で受信された制御信号に基づき、スイッチ２６をオフからオンに切り替える。この結果、負荷２４に対して、少なくとも２つの蓄電部１２（バッテリ３０）が並列に接続される。これにより、該２つの蓄電部１２の間の電圧差を電圧閾値内に抑えつつ、負荷２４への電力供給や、該２つの蓄電部１２の間での充放電を行うことができる。 Next, the ECU 14 transmits a control signal instructing the on of the switch 26 to the communication units 38 of at least two power storage units 12 via the communication line 28. As a result, the BMU 32 of at least two power storage units 12 switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, at least two power storage units 12 (batteries 30) are connected in parallel to the load 24. As a result, it is possible to supply power to the load 24 and charge / discharge between the two power storage units 12 while suppressing the voltage difference between the two power storage units 12 within the voltage threshold value.
　ＢＭＵ３２は、各バッテリ３０の電圧値等を逐次取得している。そこで、次のステップＳ６において、ＥＣＵ１４は、少なくとも２つの蓄電部１２からバッテリ３０の電圧値等の情報を取得し、取得した情報に含まれる電圧値から、少なくとも２つの蓄電部１２の間で、充放電によって、バッテリ３０の電圧値が平均化されたか否かを判定する。 The BMU 32 sequentially acquires the voltage value and the like of each battery 30. Therefore, in the next step S6, the ECU 14 acquires information such as the voltage value of the battery 30 from at least two storage units 12, and from the voltage value included in the acquired information, between at least two storage units 12. It is determined whether or not the voltage value of the battery 30 is averaged by charging / discharging.
　バッテリ３０の電圧値が平均化された場合（ステップＳ６：ＹＥＳ）、ＥＣＵ１４は、ステップＳ２に戻り、ステップＳ２、Ｓ３、Ｓ５、Ｓ６の処理を繰り返し実行する。従って、本実施形態に係る電力装置１０では、最大電圧値と最小電圧値との電圧差が電圧閾値以内になるまで（ステップＳ３：ＹＥＳ）、ＥＣＵ１４は、各蓄電部１２のバッテリ３０の電圧値の取得と、各蓄電部１２の接続の判定処理と、各スイッチ２６による各蓄電部１２の接続処理とを繰り返し行う。つまり、本実施形態では、各蓄電部１２を段階的に並列接続して、各蓄電部１２の間で充放電を行わせることにより、各蓄電部１２の電圧差を平均化させる。 When the voltage value of the battery 30 is averaged (step S6: YES), the ECU 14 returns to step S2 and repeatedly executes the processes of steps S2, S3, S5, and S6. Therefore, in the power device 10 according to the present embodiment, until the voltage difference between the maximum voltage value and the minimum voltage value is within the voltage threshold value (step S3: YES), the ECU 14 is the voltage value of the battery 30 of each power storage unit 12. , The process of determining the connection of each power storage unit 12, and the process of connecting each power storage unit 12 by each switch 26 are repeatedly performed. That is, in the present embodiment, the power storage units 12 are connected in parallel in stages, and charging / discharging is performed between the power storage units 12 to average the voltage difference of each power storage unit 12.
［３．本実施形態の動作の具体例］
　次に、上述した動作の具体例（第１実施例、第２実施例）について、図４～図１３を参照しながら説明する。 [3. Specific example of operation of this embodiment]
Next, specific examples of the above-described operations (first embodiment, second embodiment) will be described with reference to FIGS. 4 to 13.
　第１実施例は、図４～図８のように、第１～第４蓄電部１２ａ～１２ｄ（図１及び図２参照）の順に電圧値が低くなっている場合に、最大電圧値の第１蓄電部１２ａを基準に、負荷２４に対する並列接続を段階的に繰り返し行うことで、最終的に全ての蓄電部１２ａ～１２ｄを並列接続する場合を図示したものである。一方、第２実施例は、図９～図１３のように、最小電圧値の第４蓄電部１２ｄを基準に、負荷２４に対する並列接続を段階的に繰り返し行うことで、最終的に全ての蓄電部１２ａ～１２ｄを並列接続する場合を図示したものである。 In the first embodiment, as shown in FIGS. 4 to 8, when the voltage values are lowered in the order of the first to fourth power storage units 12a to 12d (see FIGS. 1 and 2), the maximum voltage value is the first. 1 The case where all the storage units 12a to 12d are finally connected in parallel by repeating the parallel connection to the load 24 stepwise with reference to the power storage unit 12a is illustrated. On the other hand, in the second embodiment, as shown in FIGS. 9 to 13, by repeating the parallel connection to the load 24 stepwise based on the fourth storage unit 12d having the minimum voltage value, all the storage is finally performed. The case where the parts 12a to 12d are connected in parallel is illustrated.
　なお、第１実施例及び第２実施例は、図４及び図９に示すように、第１～第４蓄電部１２ａ～１２ｄの接続前の電圧値は、Ｖ１～Ｖ４であり、電圧閾値をＶｔｈｒとする。また、図４～図１３では、第１～第４蓄電部１２ａ～１２ｄをＮｏ．１～Ｎｏ．４として表記している。 In the first and second embodiments, as shown in FIGS. 4 and 9, the voltage values before the connection of the first to fourth power storage units 12a to 12d are V1 to V4, and the voltage threshold value is set. Let it be Vthr. Further, in FIGS. 4 to 13, the first to fourth power storage units 12a to 12d are designated as No. 1 to No. It is written as 4.
＜３．１　第１実施例＞
　第１実施例について、図４～図７を参照しながら説明する。図４に示すように、｜Ｖ１－Ｖ４｜＞Ｖｔｈｒである（図３のステップＳ３：ＮＯ）。そのため、負荷２４（図１及び図２参照）に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続すると過電流が流れる可能性がある（図４中の「ＮＧ」の接続）。一方、第１～第３蓄電部１２ａ～１２ｃの接続、第２～第４蓄電部１２ｂ～１２ｄの接続、第１蓄電部１２ａと第２蓄電部１２ｂとの接続、第２蓄電部１２ｂと第３蓄電部１２ｃとの接続、及び、第３蓄電部１２ｃと第４蓄電部１２ｄとの接続では、接続対象の蓄電部１２の電圧値が互いに近い（隣接している）ため、電圧差が電圧閾値Ｖｔｈｒ以内となり、過電流は発生しない（図４中の「ＯＫ」の接続）。 <3.1 First Example>
The first embodiment will be described with reference to FIGS. 4 to 7. As shown in FIG. 4, | V1-V4 |> Vthr (step S3: NO in FIG. 3). Therefore, if the first to fourth power storage units 12a to 12d are connected in parallel to the load 24 (see FIGS. 1 and 2), an overcurrent may flow (“NG” connection in FIG. 4). On the other hand, the connection of the first to third storage units 12a to 12c, the connection of the second to fourth storage units 12b to 12d, the connection between the first storage unit 12a and the second storage unit 12b, the connection of the second storage unit 12b and the second In the connection with the 3 power storage unit 12c and the connection between the 3rd power storage unit 12c and the 4th power storage unit 12d, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other), so that the voltage difference is voltage. It is within the threshold voltage Vthr, and no overcurrent occurs (“OK” connection in FIG. 4).
　そこで、図４の場合、ＥＣＵ１４は、最大電圧値（電圧値Ｖ１）の第１蓄電部１２ａを基準とした、第１蓄電部１２ａと第２蓄電部１２ｂとの接続（接続Ａ）、又は、第１～第３蓄電部１２ａ～１２ｃの接続（接続Ｂ）を択一的に選択する。 Therefore, in the case of FIG. 4, the ECU 14 connects (connection A) between the first storage unit 12a and the second storage unit 12b with reference to the first storage unit 12a having the maximum voltage value (voltage value V1), or The connection (connection B) of the first to third power storage units 12a to 12c is selectively selected.
　ここで、ＥＣＵ１４が接続Ａを選択すると、ＥＣＵ１４は、通信線２８を介して、第１蓄電部１２ａ及び第２蓄電部１２ｂの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１蓄電部１２ａ及び第２蓄電部１２ｂのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオフからオンに切り替える。この結果、負荷２４に対して第１蓄電部１２ａ及び第２蓄電部１２ｂが並列に接続され、第１蓄電部１２ａと第２蓄電部１２ｂとの間で充放電が行われる（図３のステップＳ５）。 Here, when the ECU 14 selects the connection A, the ECU 14 transmits a control signal for turning on the switch 26 to the communication unit 38 of the first power storage unit 12a and the second power storage unit 12b via the communication line 28. To do. As a result, the BMU 32 of the first power storage unit 12a and the second power storage unit 12b switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the first power storage unit 12a and the second power storage unit 12b are connected in parallel to the load 24, and charging / discharging is performed between the first power storage unit 12a and the second power storage unit 12b (step of FIG. 3). S5).
　充放電の結果、図５のように、第１蓄電部１２ａの電圧値は、Ｖ１からＶ１２に低下し、一方で、第２蓄電部１２ｂの電圧値は、Ｖ２からＶ１２に上昇する。すなわち、第１蓄電部１２ａ及び第２蓄電部１２ｂの電圧値はＶ１２に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最大電圧値は、Ｖ１からＶ１２に低下する。 As a result of charging and discharging, as shown in FIG. 5, the voltage value of the first storage unit 12a decreases from V1 to V12, while the voltage value of the second storage unit 12b increases from V2 to V12. That is, the voltage values of the first power storage unit 12a and the second power storage unit 12b are averaged to V12 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V1 to V12.
　但し、図５のように、依然として、｜Ｖ１２－Ｖ４｜＞Ｖｔｈｒであるため（図３のステップＳ３：ＮＯ）、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続すると過電流が流れる可能性がある（図５中の「ＮＧ」の接続）。一方、第１～第３蓄電部１２ａ～１２ｃの接続、及び、第３蓄電部１２ｃと第４蓄電部１２ｄとの接続は、接続対象の蓄電部１２の電圧値が互いに近い（隣接している）ため、電圧差が電圧閾値Ｖｔｈｒ以内となり、過電流は発生しない（図５中の「ＯＫ」の接続）。 However, as shown in FIG. 5, since | V12-V4 |> Vthr is still obtained (step S3: NO in FIG. 3), when the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, Overcurrent may flow (“NG” connection in FIG. 5). On the other hand, in the connection of the first to third power storage units 12a to 12c and the connection between the third power storage unit 12c and the fourth power storage unit 12d, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other). ) Therefore, the voltage difference is within the voltage threshold Vthr, and no overcurrent occurs (“OK” connection in FIG. 5).
　そこで、図５の場合、ＥＣＵ１４は、最大電圧値（電圧値Ｖ１２）の第１蓄電部１２ａ及び第２蓄電部１２ｂを基準とした、第１～第３蓄電部１２ａ～１２ｃの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第１～第３蓄電部１２ａ～１２ｃの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第３蓄電部１２ａ～１２ｃのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第１～第３蓄電部１２ａ～１２ｃが並列に接続され、第１～第３蓄電部１２ａ～１２ｃの間で充放電が行われる（図３のステップＳ５）。 Therefore, in the case of FIG. 5, the ECU 14 selects the connection of the first to third storage units 12a to 12c with reference to the first storage unit 12a and the second storage unit 12b having the maximum voltage value (voltage value V12). Select. Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to third power storage units 12a to 12c via the communication line 28. As a result, the BMUs 32 of the first to third storage units 12a to 12c turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the first to third power storage units 12a to 12c are connected in parallel to the load 24, and charging / discharging is performed between the first to third power storage units 12a to 12c (step S5 in FIG. 3).
　充放電の結果、図６のように、第１蓄電部１２ａ及び第２蓄電部１２ｂの電圧値は、Ｖ１２からＶ１２３に低下し、一方で、第３蓄電部１２ｃの電圧値は、Ｖ３からＶ１２３に上昇する。すなわち、第１～第３蓄電部１２ａ～１２ｃの電圧値はＶ１２３に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最大電圧値は、Ｖ１２からＶ１２３に低下する。 As a result of charging and discharging, as shown in FIG. 6, the voltage values of the first power storage unit 12a and the second power storage unit 12b decreased from V12 to V123, while the voltage values of the third power storage unit 12c decreased from V3 to V123. Ascend to. That is, the voltage values of the first to third storage units 12a to 12c are averaged to V123 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V12 to V123.
　この場合、｜Ｖ１２３－Ｖ４｜≦Ｖｔｈｒとなるため（図３のステップＳ３：ＹＥＳ）、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続しても過電流は発生しない（図６中の「ＯＫ」の接続）。そこで、ＥＣＵ１４は、最大電圧値（電圧値Ｖ１２３）の第１～第３蓄電部１２ａ～１２ｃを基準とした、第１～第４蓄電部１２ａ～１２ｄの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第１～第４蓄電部１２ａ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第４蓄電部１２ａ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄが並列に接続され、第１～第４蓄電部１２ａ～１２ｄの間で充放電が行われる（図３のステップＳ４）。 In this case, since | V123-V4 | ≦ Vthr (step S3: YES in FIG. 3), overcurrent does not occur even if the first to fourth power storage units 12a to 12d are connected in parallel to the load 24. (Connection of "OK" in FIG. 6). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the first to third storage units 12a to 12c having the maximum voltage value (voltage value V123). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28. As a result, the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
　充放電の結果、図７のように、第１～第３蓄電部１２ａ～１２ｃの電圧値は、Ｖ１２３からＶ１２３４に低下し、一方で、第４蓄電部１２ｄの電圧値は、Ｖ４からＶ１２３４に上昇する。すなわち、第１～第４蓄電部１２ａ～１２ｄの電圧値はＶ１２３４に平均化される。 As a result of charging and discharging, as shown in FIG. 7, the voltage values of the first to third storage units 12a to 12c decreased from V123 to V1234, while the voltage values of the fourth storage unit 12d changed from V4 to V1234. To rise. That is, the voltage values of the first to fourth storage units 12a to 12d are averaged to V1234.
　ところで、上記の説明では、図４の接続Ａを択一的に選択した場合について説明した。ＥＣＵ１４が接続Ｂを択一的に選択した場合、ＥＣＵ１４は、通信線２８を介して、第１～第３蓄電部１２ａ～１２ｃの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第３蓄電部１２ａ～１２ｃのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオフからオンに切り替える。この結果、負荷２４に対して第１～第３蓄電部１２ａ～１２ｃが並列に接続され、第１～第３蓄電部１２ａ～１２ｃの間で充放電が行われる（図３のステップＳ５）。 By the way, in the above description, the case where the connection A in FIG. 4 is selectively selected has been described. When the ECU 14 selectively selects the connection B, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to third storage units 12a to 12c via the communication line 28. Send. As a result, the BMUs 32 of the first to third storage units 12a to 12c switch the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the first to third power storage units 12a to 12c are connected in parallel to the load 24, and charging / discharging is performed between the first to third power storage units 12a to 12c (step S5 in FIG. 3).
　充放電の結果、図８のように、第１蓄電部１２ａの電圧値は、Ｖ１からＶ１２３に低下し、第２蓄電部１２ｂの電圧値は、Ｖ２（＝Ｖ１２３）を維持し、第３蓄電部１２ｃの電圧値は、Ｖ３からＶ１２３に上昇する。すなわち、第１～第３蓄電部１２ａ～１２ｃの電圧値はＶ１２３に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最大電圧値は、Ｖ１からＶ１２３に低下する。 As a result of charging and discharging, as shown in FIG. 8, the voltage value of the first power storage unit 12a drops from V1 to V123, and the voltage value of the second power storage unit 12b maintains V2 (= V123), and the third power storage unit The voltage value of unit 12c rises from V3 to V123. That is, the voltage values of the first to third storage units 12a to 12c are averaged to V123 (step S6: YES in FIG. 3). As a result, the maximum voltage value drops from V1 to V123.
　この場合、｜Ｖ１２３－Ｖ４｜≦Ｖｔｈｒとなるため（図３のステップＳ３：ＹＥＳ）、図６の場合と同様に、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続しても過電流は発生しない（図８中の「ＯＫ」の接続）。そこで、ＥＣＵ１４は、最大電圧値（電圧値Ｖ１２３）の第１～第３蓄電部１２ａ～１２ｃを基準とした、第１～第４蓄電部１２ａ～１２ｄの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第１～第４蓄電部１２ａ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第４蓄電部１２ａ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄが並列に接続され、第１～第４蓄電部１２ａ～１２ｄの間で充放電が行われる（図３のステップＳ４）。 In this case, since | V123-V4 | ≦ Vthr (step S3: YES in FIG. 3), the first to fourth power storage units 12a to 12d are connected in parallel to the load 24 as in the case of FIG. However, no overcurrent occurs (“OK” connection in FIG. 8). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the first to third storage units 12a to 12c having the maximum voltage value (voltage value V123). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28. As a result, the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
　この場合も、充放電の結果、図７のように、第１～第３蓄電部１２ａ～１２ｃの電圧値は、Ｖ１２３からＶ１２３４に低下し、一方で、第４蓄電部１２ｄの電圧値は、Ｖ４からＶ１２３４に上昇する。接続Ｂを選択した場合、接続Ａの場合と比較して、第１～第４蓄電部１２ａ～１２ｄの電圧値をＶ１２３４に速やかに平均化することができる。 Also in this case, as a result of charging / discharging, as shown in FIG. 7, the voltage values of the first to third storage units 12a to 12c decrease from V123 to V1234, while the voltage values of the fourth storage units 12d are increased. It rises from V4 to V1234. When the connection B is selected, the voltage values of the first to fourth power storage units 12a to 12d can be quickly averaged to V1234 as compared with the case of the connection A.
＜３．２　第２実施例＞
　第２実施例について、図９～図１２を参照しながら説明する。図９に示すように、｜Ｖ１－Ｖ４｜＞Ｖｔｈｒである（図３のステップＳ３：ＮＯ）。そのため、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続すると過電流が流れる可能性がある（図９中の「ＮＧ」の接続）。一方、第１～第３蓄電部１２ａ～１２ｃの接続、第２～第４蓄電部１２ｂ～１２ｄの接続、第１蓄電部１２ａと第２蓄電部１２ｂとの接続、第２蓄電部１２ｂと第３蓄電部１２ｃとの接続、及び、第３蓄電部１２ｃと第４蓄電部１２ｄとの接続では、接続対象の蓄電部１２の電圧値が互いに近く（隣接し）、電圧差が電圧閾値Ｖｔｈｒ以内となるため、過電流は発生しない（図９中の「ＯＫ」の接続）。 <3.2 Second Example>
The second embodiment will be described with reference to FIGS. 9 to 12. As shown in FIG. 9, | V1-V4 |> Vthr (step S3: NO in FIG. 3). Therefore, if the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, an overcurrent may flow (connection of "NG" in FIG. 9). On the other hand, the connection of the first to third storage units 12a to 12c, the connection of the second to fourth storage units 12b to 12d, the connection between the first storage unit 12a and the second storage unit 12b, the connection of the second storage unit 12b and the second In the connection with the 3 power storage unit 12c and the connection between the 3rd power storage unit 12c and the 4th power storage unit 12d, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other), and the voltage difference is within the voltage threshold Vthr. Therefore, no overcurrent is generated (“OK” connection in FIG. 9).
　そこで、図９の場合、ＥＣＵ１４は、最小電圧値（電圧値Ｖ４）の第４蓄電部１２ｄを基準とした、第３蓄電部１２ｃと第４蓄電部１２ｄとの接続（接続Ｃ）、又は、第２～第４蓄電部１２ｂ～１２ｄの接続（接続Ｄ）を択一的に選択する。 Therefore, in the case of FIG. 9, the ECU 14 connects (connection C) between the third storage unit 12c and the fourth storage unit 12d with reference to the fourth storage unit 12d having the minimum voltage value (voltage value V4). The connection (connection D) of the second to fourth power storage units 12b to 12d is selectively selected.
　ここで、ＥＣＵ１４が接続Ｃを選択すると、ＥＣＵ１４は、通信線２８を介して、第３蓄電部１２ｃ及び第４蓄電部１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第３蓄電部１２ｃ及び第４蓄電部１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオフからオンに切り替える。この結果、負荷２４に対して第３蓄電部１２ｃ及び第４蓄電部１２ｄが並列に接続され、第３蓄電部１２ｃと第４蓄電部１２ｄとの間で充放電が行われる（図３のステップＳ５）。 Here, when the ECU 14 selects the connection C, the ECU 14 transmits a control signal for turning on the switch 26 to the communication unit 38 of the third storage unit 12c and the fourth storage unit 12d via the communication line 28. To do. As a result, the BMU 32 of the third power storage unit 12c and the fourth power storage unit 12d switches the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the third power storage unit 12c and the fourth power storage unit 12d are connected in parallel to the load 24, and charging / discharging is performed between the third power storage unit 12c and the fourth power storage unit 12d (step of FIG. 3). S5).
　充放電の結果、図１０のように、第３蓄電部１２ｃの電圧値は、Ｖ３からＶ３４に低下し、一方で、第４蓄電部１２ｄの電圧値は、Ｖ４からＶ３４に上昇する。すなわち、第３蓄電部１２ｃ及び第４蓄電部１２ｄの電圧値はＶ３４に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最小電圧値は、Ｖ４からＶ３４に上昇する。 As a result of charging and discharging, as shown in FIG. 10, the voltage value of the third storage unit 12c decreases from V3 to V34, while the voltage value of the fourth storage unit 12d increases from V4 to V34. That is, the voltage values of the third power storage unit 12c and the fourth power storage unit 12d are averaged to V34 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V4 to V34.
　但し、依然として、｜Ｖ１－Ｖ３４｜＞Ｖｔｈｒであるため（図３のステップＳ３：ＮＯ）、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続すると過電流が流れる可能性がある（図１０中の「ＮＧ」の接続）。一方、第２～第４蓄電部１２ｂ～１２ｄの接続、及び、第１蓄電部１２ａと第２蓄電部１２ｂとの接続は、接続対象の蓄電部１２の電圧値が互いに近く（隣接し）、電圧差が電圧閾値Ｖｔｈｒ以内となるため、過電流は発生しない（図１０中の「ＯＫ」の接続）。 However, since it is still | V1-V34 |> Vthr (step S3: NO in FIG. 3), if the first to fourth storage units 12a to 12d are connected in parallel to the load 24, an overcurrent may flow. There is (“NG” connection in FIG. 10). On the other hand, in the connection of the second to fourth power storage units 12b to 12d and the connection between the first power storage unit 12a and the second power storage unit 12b, the voltage values of the power storage units 12 to be connected are close to each other (adjacent to each other). Since the voltage difference is within the voltage threshold Vthr, no overcurrent occurs (“OK” connection in FIG. 10).
　そこで、ＥＣＵ１４は、最小電圧値（電圧値Ｖ３４）の第３蓄電部１２ｃ及び第４蓄電部１２ｄを基準とした、第２～第４蓄電部１２ｂ～１２ｄの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第２～第４蓄電部１２ｂ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第２～第４蓄電部１２ｂ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第２～第４蓄電部１２ｂ～１２ｄが並列に接続され、第２～第４蓄電部１２ｂ～１２ｄの間で充放電が行われる（図３のステップＳ５）。 Therefore, the ECU 14 selectively selects the connection of the second to fourth storage units 12b to 12d based on the third storage unit 12c and the fourth storage unit 12d having the minimum voltage value (voltage value V34). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the second to fourth power storage units 12b to 12d via the communication line 28. As a result, the BMUs 32 of the second to fourth storage units 12b to 12d turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the second to fourth power storage units 12b to 12d are connected in parallel to the load 24, and charging and discharging are performed between the second to fourth power storage units 12b to 12d (step S5 in FIG. 3).
　充放電の結果、図１１のように、第２蓄電部１２ｂの電圧値は、Ｖ２からＶ２３４に低下し、一方で、第３蓄電部１２ｃ及び第４蓄電部１２ｄの電圧値は、Ｖ３４からＶ２３４に上昇する。すなわち、第２～第４蓄電部１２ｂ～１２ｄの電圧値はＶ２３４に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最小電圧値は、Ｖ３４からＶ２３４に上昇する。 As a result of charging and discharging, as shown in FIG. 11, the voltage value of the second power storage unit 12b drops from V2 to V234, while the voltage values of the third power storage unit 12c and the fourth power storage unit 12d decrease from V34 to V234. Ascend to. That is, the voltage values of the second to fourth storage units 12b to 12d are averaged to V234 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V34 to V234.
　この場合、｜Ｖ１－Ｖ２３４｜≦Ｖｔｈｒとなるため（図３のステップＳ３：ＹＥＳ）、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続しても過電流は発生しない（図１１中の「ＯＫ」の接続）。そこで、ＥＣＵ１４は、最小電圧値（電圧値Ｖ２３４）の第２～第４蓄電部１２ｂ～１２ｄを基準とした、第１～第４蓄電部１２ａ～１２ｄの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第１～第４蓄電部１２ａ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第４蓄電部１２ａ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄが並列に接続され、第１～第４蓄電部１２ａ～１２ｄの間で充放電が行われる（図３のステップＳ４）。 In this case, since | V1-V234 | ≦ Vthr (step S3: YES in FIG. 3), overcurrent does not occur even if the first to fourth power storage units 12a to 12d are connected in parallel to the load 24. (Connection of "OK" in FIG. 11). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the second to fourth storage units 12b to 12d having the minimum voltage value (voltage value V234). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28. As a result, the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
　充放電の結果、図１２のように、第１蓄電部１２ａの電圧値は、Ｖ１からＶ１２３４に低下し、一方で、第２～第４蓄電部１２ｂ～１２ｄの電圧値は、Ｖ２３４からＶ１２３４に上昇する。すなわち、第１～第４蓄電部１２ａ～１２ｄの電圧値はＶ１２３４に平均化される。 As a result of charging and discharging, as shown in FIG. 12, the voltage value of the first power storage unit 12a drops from V1 to V1234, while the voltage values of the second to fourth power storage units 12b to 12d change from V234 to V1234. To rise. That is, the voltage values of the first to fourth storage units 12a to 12d are averaged to V1234.
　ところで、上記の説明では、図９の接続Ｃを択一的に選択した場合について説明した。ＥＣＵ１４が接続Ｄを択一的に選択した場合、ＥＣＵ１４は、通信線２８を介して、第２～第４蓄電部１２ｂ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第２～第４蓄電部１２ｂ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオフからオンに切り替える。この結果、負荷２４に対して第２～第４蓄電部１２ｂ～１２ｄが並列に接続され、第２～第４蓄電部１２ｂ～１２ｄの間で充放電が行われる（図３のステップＳ５）。 By the way, in the above description, the case where the connection C in FIG. 9 is selectively selected has been described. When the ECU 14 selectively selects the connection D, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the second to fourth power storage units 12b to 12d via the communication line 28. Send. As a result, the BMUs 32 of the second to fourth storage units 12b to 12d switch the switch 26 from off to on based on the control signal received by the communication unit 38. As a result, the second to fourth power storage units 12b to 12d are connected in parallel to the load 24, and charging and discharging are performed between the second to fourth power storage units 12b to 12d (step S5 in FIG. 3).
　充放電の結果、図１３のように、第２蓄電部１２ｂの電圧値は、Ｖ２からＶ２３４に低下し、第３蓄電部１２ｃの電圧値は、Ｖ３（＝Ｖ２３４）を維持し、第４蓄電部１２ｄの電圧値は、Ｖ４からＶ２３４に上昇する。すなわち、第２～第４蓄電部１２ｂ～１２ｄの電圧値はＶ２３４に平均化される（図３のステップＳ６：ＹＥＳ）。この結果、最小電圧値は、Ｖ４からＶ２３４に上昇する。 As a result of charging and discharging, as shown in FIG. 13, the voltage value of the second storage unit 12b drops from V2 to V234, and the voltage value of the third storage unit 12c maintains V3 (= V234), and the fourth storage unit The voltage value of unit 12d rises from V4 to V234. That is, the voltage values of the second to fourth storage units 12b to 12d are averaged to V234 (step S6: YES in FIG. 3). As a result, the minimum voltage value rises from V4 to V234.
　この場合、｜Ｖ１－Ｖ２３４｜≦Ｖｔｈｒであるため（図３のステップＳ３：ＹＥＳ）、図１１の場合と同様に、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄを並列に接続しても過電流は発生しない（図１３中の「ＯＫ」の接続）。そこで、ＥＣＵ１４は、最小電圧値（電圧値Ｖ２３４）の第２～第４蓄電部１２ｂ～１２ｄを基準とした、第１～第４蓄電部１２ａ～１２ｄの接続を択一的に選択する。次に、ＥＣＵ１４は、通信線２８を介して、第１～第４蓄電部１２ａ～１２ｄの通信部３８に、スイッチ２６をオンにするための制御信号を送信する。これにより、第１～第４蓄電部１２ａ～１２ｄのＢＭＵ３２は、通信部３８が受信した制御信号に基づきスイッチ２６をオンにする。この結果、負荷２４に対して第１～第４蓄電部１２ａ～１２ｄが並列に接続され、第１～第４蓄電部１２ａ～１２ｄの間で充放電が行われる（図３のステップＳ４）。 In this case, since | V1-V234 | ≦ Vthr (step S3: YES in FIG. 3), the first to fourth power storage units 12a to 12d are connected in parallel to the load 24 as in the case of FIG. However, no overcurrent is generated (“OK” connection in FIG. 13). Therefore, the ECU 14 selectively selects the connection of the first to fourth storage units 12a to 12d based on the second to fourth storage units 12b to 12d having the minimum voltage value (voltage value V234). Next, the ECU 14 transmits a control signal for turning on the switch 26 to the communication units 38 of the first to fourth power storage units 12a to 12d via the communication line 28. As a result, the BMUs 32 of the first to fourth storage units 12a to 12d turn on the switch 26 based on the control signal received by the communication unit 38. As a result, the first to fourth power storage units 12a to 12d are connected in parallel to the load 24, and charging and discharging are performed between the first to fourth power storage units 12a to 12d (step S4 in FIG. 3).
　この場合も、充放電の結果、図１２のように、第１蓄電部１２ａの電圧値は、Ｖ１からＶ１２３４に低下し、一方で、第２～第４蓄電部１２ｂ～１２ｄの電圧値は、Ｖ２３４からＶ１２３４に上昇する。接続Ｄを選択した場合、接続Ｃの場合と比較して、第１～第４蓄電部１２ａ～１２ｄの電圧値をＶ１２３４に速やかに平均化することができる。 Also in this case, as a result of charging / discharging, the voltage value of the first power storage unit 12a drops from V1 to V1234 as shown in FIG. 12, while the voltage values of the second to fourth power storage units 12b to 12d are increased. It rises from V234 to V1234. When the connection D is selected, the voltage values of the first to fourth storage units 12a to 12d can be quickly averaged to V1234 as compared with the case of the connection C.
［４．変形例］
　本実施形態に係る電力装置１０は、図１４に示す変形例の構成であってもよい。この変形例では、各蓄電部１２（１２ａ～１２ｄ）は、バッテリ３０及び温度センサ３６のみ有する。各バッテリ３０には、該バッテリ３０の電圧値を逐次検出する電圧センサ４０が並列に接続されている。さらに、各バッテリ３０の正極端子は、電流センサ４２及びスイッチ２６を介して負荷２４の正極端子に接続されている。さらにまた、各バッテリ３０の負極端子は、負荷２４の負極端子に接続されている。電流センサ４２は、バッテリ３０に流れる電流の電流値を逐次検出する。 [4. Modification example]
The electric power device 10 according to the present embodiment may have a configuration of a modified example shown in FIG. In this modification, each power storage unit 12 (12a to 12d) has only the battery 30 and the temperature sensor 36. A voltage sensor 40 that sequentially detects the voltage value of the battery 30 is connected in parallel to each battery 30. Further, the positive electrode terminal of each battery 30 is connected to the positive electrode terminal of the load 24 via the current sensor 42 and the switch 26. Furthermore, the negative electrode terminal of each battery 30 is connected to the negative electrode terminal of the load 24. The current sensor 42 sequentially detects the current value of the current flowing through the battery 30.
　ＥＣＵ１４は、各温度センサ３６、各電圧センサ４０及び各電流センサ４２とアナログ信号線４４を介して接続されている。ＥＣＵ１４は、各温度センサ３６が検出したバッテリ３０の温度、各電圧センサ４０が検出したバッテリ３０の電圧値、各電流センサ４２が検出した電流値を逐次取得する。従って、この変形例でも、ＥＣＵ１４は、上述したスイッチ２６の接続処理等を実行することが可能である。 The ECU 14 is connected to each temperature sensor 36, each voltage sensor 40, and each current sensor 42 via an analog signal line 44. The ECU 14 sequentially acquires the temperature of the battery 30 detected by each temperature sensor 36, the voltage value of the battery 30 detected by each voltage sensor 40, and the current value detected by each current sensor 42. Therefore, even in this modification, the ECU 14 can execute the connection process of the switch 26 described above.
　上記のように、図１及び図２の構成では、ＥＣＵ１４は、各蓄電部１２から電圧値等を取得する。また、図１４の構成では、ＥＣＵ１４は、電圧センサ４０が検出した電圧値がＥＣＵ１４に入力される。本実施形態では、これらの構成に限定されることなく、ＥＣＵ１４は、各蓄電部１２からの情報に基づき、電圧値を推定してもよい。 As described above, in the configurations of FIGS. 1 and 2, the ECU 14 acquires a voltage value or the like from each power storage unit 12. Further, in the configuration of FIG. 14, the ECU 14 inputs the voltage value detected by the voltage sensor 40 to the ECU 14. In the present embodiment, the ECU 14 may estimate the voltage value based on the information from each power storage unit 12, without being limited to these configurations.
［５．本実施形態の効果］
　以上説明したように、本実施形態は、少なくとも３つの蓄電部１２（１２ａ～１２ｄ）を有する電力装置１０及びその制御方法に関する。 [5. Effect of this embodiment]
As described above, the present embodiment relates to an electric power device 10 having at least three power storage units 12 (12a to 12d) and a control method thereof.
　この場合、電力装置１０は、蓄電部１２の電圧値をそれぞれ取得する電圧取得部、及び、取得した蓄電部１２の電圧値に基づいて、蓄電部１２のうち、電圧値が隣接する２つの蓄電部１２を相互に接続する接続部として機能するＥＣＵ１４を有する。 In this case, the electric power device 10 stores two electricity storage units 12 having adjacent voltage values based on the voltage acquisition unit that acquires the voltage value of the power storage unit 12 and the acquired voltage value of the power storage unit 12. It has an ECU 14 that functions as a connecting unit that connects the units 12 to each other.
　また、電力装置１０の制御方法は、ＥＣＵ１４が蓄電部１２の電圧値をそれぞれ取得するステップ（ステップＳ２）と、取得した蓄電部１２の電圧値に基づいて、蓄電部１２のうち、電圧値が隣接する２つの蓄電部１２を相互に接続するステップ（ステップＳ４、Ｓ５）とを有する。 Further, in the control method of the electric power device 10, the voltage value of the power storage unit 12 is determined based on the step (step S2) in which the ECU 14 acquires the voltage value of the power storage unit 12 and the acquired voltage value of the power storage unit 12. It has a step (steps S4 and S5) of connecting two adjacent power storage units 12 to each other.
　このように、本実施形態では、少なくとも３つの蓄電部１２の中から、電圧値が隣接する２つの蓄電部１２を選択して相互に接続する。これにより、回路を追加することなく、電気的な制御のみで蓄電部１２を接続し、過電流の発生を抑制することができる。この結果、コストの影響を最小限に抑えることができる。従って、全ての蓄電部１２を同時に接続する場合や、電圧値が互いに離れている（隣接していない）２つ以上の蓄電部１２を接続する場合と比較して、電圧差を低減しつつ、蓄電部１２に過電流が流れることを抑制することができる。 As described above, in the present embodiment, two power storage units 12 having adjacent voltage values are selected from at least three power storage units 12 and connected to each other. As a result, the power storage unit 12 can be connected only by electrical control without adding a circuit, and the occurrence of overcurrent can be suppressed. As a result, the cost impact can be minimized. Therefore, as compared with the case where all the power storage units 12 are connected at the same time or when two or more power storage units 12 whose voltage values are separated from each other (not adjacent to each other) are connected, the voltage difference is reduced while reducing the voltage difference. It is possible to prevent an overcurrent from flowing through the power storage unit 12.
　この場合、ＥＣＵ１４は、電圧値が最大である最大電圧値（例えば、Ｖ１）、又は、電圧値が最小である最小電圧値（例えば、Ｖ４）の蓄電部１２と、該蓄電部１２と電圧値が隣接する蓄電部１２とを相互に接続する。これにより、最大電圧値又は最小電圧値の蓄電部１２を基準として、２つの蓄電部１２が接続される。この結果、最大電圧値が低下するか、又は、最低電圧値が上昇する作用が得られる。従って、各蓄電部１２の全体の電圧差が確実に低減され、過電流の発生を効率よく抑制することができる。 In this case, the ECU 14 has a power storage unit 12 having a maximum voltage value (for example, V1) having a maximum voltage value or a minimum voltage value (for example, V4) having a minimum voltage value, and the power storage unit 12 and a voltage value. Connects to the adjacent power storage unit 12 to each other. As a result, the two power storage units 12 are connected with reference to the power storage unit 12 having the maximum voltage value or the minimum voltage value. As a result, the maximum voltage value decreases or the minimum voltage value increases. Therefore, the overall voltage difference of each power storage unit 12 is surely reduced, and the occurrence of overcurrent can be efficiently suppressed.
　また、ＥＣＵ１４は、最大電圧値の蓄電部１２と、該蓄電部１２と電圧値が隣接する蓄電部１２とを相互に接続することが好ましい。蓄電部１２の電圧値が高い程、内部抵抗値が低くなり、充放電の際に流れる電流の電流値が大きくなる。従って、最大電圧値の蓄電部１２を基準として、２つの蓄電部１２を接続することで、接続した各蓄電部１２の電圧値を速やかに平均化することが可能となる。また、蓄電部１２の電圧値が高い程、蓄電部１２が劣化しやすい傾向があるため、電圧差を電圧閾値以内に収めつつ接続することで、過電流の発生や蓄電部１２の劣化を抑制しつつ、蓄電部１２の電圧値を平均化することができる。 Further, it is preferable that the ECU 14 interconnects the power storage unit 12 having the maximum voltage value and the power storage unit 12 having the voltage value adjacent to the power storage unit 12. The higher the voltage value of the power storage unit 12, the lower the internal resistance value and the larger the current value of the current flowing during charging / discharging. Therefore, by connecting the two power storage units 12 with the maximum voltage value of the power storage unit 12 as a reference, the voltage values of the connected power storage units 12 can be quickly averaged. Further, the higher the voltage value of the power storage unit 12, the more easily the power storage unit 12 deteriorates. Therefore, by connecting while keeping the voltage difference within the voltage threshold value, the generation of overcurrent and the deterioration of the power storage unit 12 are suppressed. While doing so, the voltage value of the power storage unit 12 can be averaged.
　この場合、最大電圧値と最小電圧値との電圧差が所定の電圧閾値以内になるまで、ＥＣＵ１４による蓄電部１２の電圧値の取得と、蓄電部１２の接続とが繰り返し行われる。これにより、過電流の発生を抑制しつつ、全ての蓄電部１２を接続して、電圧値を確実に平均化することが可能となる。 In this case, the acquisition of the voltage value of the power storage unit 12 by the ECU 14 and the connection of the power storage unit 12 are repeatedly performed until the voltage difference between the maximum voltage value and the minimum voltage value is within a predetermined voltage threshold value. As a result, it is possible to connect all the power storage units 12 and reliably average the voltage values while suppressing the occurrence of overcurrent.
　また、ＥＣＵ１４は、電圧値が略同一の２つの蓄電部１２を含む場合、該２つの蓄電部１２と、該２つの蓄電部１２と電圧値が隣接する蓄電部１２との３つの蓄電部１２を相互に接続する。これにより、速やかに且つ効率よく各蓄電部１２の電圧値を平均化することができる。 Further, when the ECU 14 includes two power storage units 12 having substantially the same voltage value, the ECU 14 has three power storage units 12 including the two power storage units 12 and the two power storage units 12 and the power storage units 12 having voltage values adjacent to each other. To interconnect. As a result, the voltage values of each power storage unit 12 can be averaged quickly and efficiently.
　この場合、３つの蓄電部１２は、負荷２４に対して互いに並列に接続されるので、各蓄電部１２から負荷２４に電力を供給することが可能となる。 In this case, since the three power storage units 12 are connected to the load 24 in parallel with each other, it is possible to supply electric power from each power storage unit 12 to the load 24.
　また、３つの蓄電部１２とは異なる内蔵バッテリ１８（他の蓄電部）が、負荷２４に対して蓄電部１２と共に並列に接続される。これにより、内蔵バッテリ１８から負荷２４への電力供給や、内蔵バッテリ１８から各蓄電部１２に電力供給を行って該各蓄電部１２を起動させることが可能となる。 Further, a built-in battery 18 (another power storage unit) different from the three power storage units 12 is connected to the load 24 in parallel with the power storage unit 12. As a result, it is possible to supply electric power from the built-in battery 18 to the load 24 and to supply electric power from the built-in battery 18 to each power storage unit 12 to start each power storage unit 12.
　また、ＥＣＵ１４は、電圧値が隣接する２つの蓄電部１２の電圧差が電圧閾値を超える場合には、２つの蓄電部１２の相互の接続を禁止する。これにより、過電流の発生を確実に抑制することができる。 Further, when the voltage difference between the two storage units 12 having adjacent voltage values exceeds the voltage threshold value, the ECU 14 prohibits the connection of the two storage units 12 to each other. As a result, the occurrence of overcurrent can be reliably suppressed.
　また、電力装置１０は、３つの蓄電部１２のうち、いずれか２つの蓄電部１２を相互に接続するスイッチ２６（二者接続回路）を３つ備える。これにより、ＥＣＵ１４から個々のスイッチ２６を電気的に制御することができる。 Further, the electric power device 10 includes three switches 26 (two-way connection circuit) for connecting any two power storage units 12 to each other among the three power storage units 12. As a result, the individual switches 26 can be electrically controlled from the ECU 14.
　この場合、ＥＣＵ１４は、スイッチ２６の１つを選択することで、蓄電部１２を相互に接続することができる。 In this case, the ECU 14 can connect the power storage units 12 to each other by selecting one of the switches 26.
　なお、本発明は、上述の実施形態に限らず、この明細書の記載内容に基づき、種々の構成を採り得ることは勿論である。 It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted based on the contents described in this specification.

Claims (11)

  1. 　少なくとも３つの蓄電部（１２、１２ａ～１２ｄ）を有する電力装置（１０）において、
    　前記蓄電部の電圧値をそれぞれ取得する電圧取得部（１４）と、
    　前記電圧取得部が取得した前記蓄電部の電圧値に基づいて、前記蓄電部のうち、前記電圧値が隣接する２つの前記蓄電部を相互に接続する接続部（１４）と、
    　を有する、電力装置。     In the electric power device (10) having at least three power storage units (12, 12a to 12d),
    A voltage acquisition unit (14) for acquiring the voltage value of the power storage unit, and
    Based on the voltage value of the power storage unit acquired by the voltage acquisition unit, the connection unit (14) of the power storage unit that connects the two power storage units adjacent to each other with the voltage value is
    Has a power device.
  2. 　請求項１記載の電力装置において、
    　前記接続部は、前記電圧値が最大である最大電圧値、又は、前記電圧値が最小である最小電圧値の前記蓄電部と、該蓄電部と前記電圧値が隣接する前記蓄電部とを相互に接続する、電力装置。     In the power device according to claim 1,
    In the connection unit, the power storage unit having the maximum voltage value having the maximum voltage value or the minimum voltage value having the minimum voltage value and the power storage unit having the voltage value adjacent to the power storage unit are mutually connected with each other. A power device that connects to.
  3. 　請求項２記載の電力装置において、
    　前記接続部は、前記最大電圧値の前記蓄電部と、該蓄電部と前記電圧値が隣接する前記蓄電部とを相互に接続する、電力装置。     In the power device according to claim 2,
    The connection unit is a power device that interconnects the power storage unit having the maximum voltage value and the power storage unit having the voltage value adjacent to the power storage unit.
  4. 　請求項２又は３記載の電力装置において、
    　前記最大電圧値と前記最小電圧値との電圧差が所定の閾値以内になるまで、前記電圧取得部による前記蓄電部の電圧値の取得と、前記接続部による前記蓄電部の接続とを繰り返し行う、電力装置。     In the electric power device according to claim 2 or 3.
    The acquisition of the voltage value of the power storage unit by the voltage acquisition unit and the connection of the power storage unit by the connection unit are repeated until the voltage difference between the maximum voltage value and the minimum voltage value is within a predetermined threshold value. , Power equipment.
  5. 　請求項１～４のいずれか１項に記載の電力装置において、
    　前記接続部は、前記電圧値が略同一の２つの前記蓄電部を含む場合、該２つの前記蓄電部と、該２つの前記蓄電部と前記電圧値が隣接する前記蓄電部との３つの前記蓄電部を相互に接続する、電力装置。     In the electric power device according to any one of claims 1 to 4.
    When the connection unit includes two power storage units having substantially the same voltage value, the three power storage units, the two power storage units, and the two power storage units adjacent to each other and the voltage values are adjacent to each other. An electric power device that connects power storage units to each other.
  6. 　請求項１～５のいずれか１項に記載の電力装置において、
    　３つの前記蓄電部は、負荷（２４）に対して互いに並列に接続される、電力装置。     In the electric power device according to any one of claims 1 to 5.
    A power device in which the three power storage units are connected to each other in parallel with respect to the load (24).
  7. 　請求項６記載の電力装置において、
    　３つの前記蓄電部とは異なる他の蓄電部（１８）が、前記負荷に対して前記蓄電部と共に並列に接続される、電力装置。     In the power device according to claim 6,
    A power device in which three other power storage units (18) different from the power storage unit are connected in parallel with the power storage unit to the load.
  8. 　請求項１～７のいずれか１項に記載の電力装置において、
    　前記接続部は、前記電圧値が隣接する２つの前記蓄電部の電圧差が所定の閾値を超える場合には、２つの前記蓄電部の相互の接続を禁止する、電力装置。     In the electric power device according to any one of claims 1 to 7.
    The connection unit is a power device that prohibits the connection of two power storage units to each other when the voltage difference between two power storage units adjacent to each other exceeds a predetermined threshold value.
  9. 　請求項１～８のいずれか１項に記載の電力装置において、
    　３つの前記蓄電部のうち、いずれか２つの前記蓄電部を相互に接続する二者接続回路（２６）を３つ備える、電力装置。     In the electric power device according to any one of claims 1 to 8.
    A power device including three two-way connection circuits (26) that connect any two of the three power storage units to each other.
  10. 　請求項９記載の電力装置において、
    　前記接続部は、前記二者接続回路の１つを選択することによって、前記蓄電部を相互に接続する、電力装置。     In the power device according to claim 9.
    The connection unit is a power device that connects the power storage units to each other by selecting one of the two-party connection circuits.
  11. 　少なくとも３つの蓄電部（１２、１２ａ～１２ｄ）を有する電力装置（１０）の制御方法において、
    　電圧取得部（１４）によって前記蓄電部の電圧値をそれぞれ取得するステップと、
    　前記電圧取得部が取得した前記蓄電部の電圧値に基づいて、前記蓄電部のうち、前記電圧値が隣接する２つの前記蓄電部を相互に接続するステップと、
    　を有する、電力装置の制御方法。     In the control method of the electric power device (10) having at least three power storage units (12, 12a to 12d),
    A step of acquiring the voltage value of the power storage unit by the voltage acquisition unit (14), and
    Based on the voltage value of the power storage unit acquired by the voltage acquisition unit, the step of connecting the two power storage units having the voltage values adjacent to each other among the power storage units,
    A method of controlling an electric power device.
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WO2024071278A1 (en) * 2022-09-29 2024-04-04 株式会社Ｇｓユアサ Electricity storage system and electricity storage bank insertion method

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JP2009033936A (en) * 2007-07-30 2009-02-12 Toshiba Corp Parallel-connected energy storage system
JP2014161211A (en) * 2013-01-22 2014-09-04 Gs Yuasa Corp Connection information acquisition device for power storage units

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JP2009033936A (en) * 2007-07-30 2009-02-12 Toshiba Corp Parallel-connected energy storage system
JP2014161211A (en) * 2013-01-22 2014-09-04 Gs Yuasa Corp Connection information acquisition device for power storage units

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WO2024071278A1 (en) * 2022-09-29 2024-04-04 株式会社Ｇｓユアサ Electricity storage system and electricity storage bank insertion method

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