BATTERY SYSTEM CONTROL DEVICE AND BATTERY SYSTEM

• US 20180241095A1
• Filed: 11/02/2017
• Published: 08/23/2018
• Est. Priority Date: 02/21/2017
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Subaru Corp.
• Inventors: NOZAKI, Yuichiro
• Granted Patent: US 10,797,360 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 50/75 using propulsion power supplied by both fuel cells and batteries
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04626 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/24 : using discharge tubes or semiconductor devices
• CPC Class Codes: H02J 7/34 : Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 7/342 : The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A battery system control device includes a load, a secondary battery connected to the load via a first power converter converting a voltage by a switching operation, a fuel cell, and a control unit. The battery discharges power supplied to the load. The fuel cell is connected to the load and to the battery and the first power converter, via a second power converter converting a voltage. The fuel cell generates low voltage power. The control unit charges the battery using the generated power from the fuel cell. The control unit includes fuel cell and secondary battery controllers. The fuel cell controller steps up the power generated by the fuel cell to a voltage chargeable by the battery to be supplied to the load by the second power converter. The secondary battery controller directly connects the load and the battery by stopping the switching operation of the first power converter.

Claims

1. A battery system control device, comprising:

a load;

a secondary battery that is connected to the load via a first power converter capable of converting a voltage by performing a switching operation, the secondary battery being capable of discharging power supplied to the load;

a fuel cell, being connected to the load, that is connected in parallel with the secondary battery and the first power converter, via a second power converter capable of converting a voltage by performing a switching operation, the fuel cell being capable of generating electric power of a low voltage as compared with a voltage of the secondary battery, and

a control unit capable of executing a charging control mode for charging the secondary battery using the generated power from the fuel cell, wherein

the control unit comprises;

a fuel cell controller configured to step up the electric power generated by the fuel cell to a voltage that is chargeable by the secondary battery, and supply the stepped-up electric power to the load side of the second power converter by causing the second power converter to perform the switching operation during execution of the charging control mode; and

a secondary battery controller configured to directly connect the load side of the first power converter and the secondary battery by stopping the switching operation of the first power converter during the execution of the charging control mode.

2. The battery system control device according to claim 1, wherein

the control unit starts the charging control mode when a remaining capacity of the secondary battery falls below a predetermined value.

3. The battery system control device according to claim 1, wherein

the fuel cell controller controls an output of the fuel cell, at a start of the charging control mode, to be a reference output that prioritizes power generation efficiency of the fuel cell.

4. The battery system control device according to claim 2, wherein

the fuel cell controller controls an output of the fuel cell, at a start of the charging control mode, to be a reference output that prioritizes power generation efficiency of the fuel cell.

5. The battery system control device according to claim 3, wherein

the fuel cell controller controls the output of the fuel cell to be larger than the reference output when the remaining capacity of the secondary battery decreases after the start of the charging control mode.

6. The battery system control device according to claim 4, wherein

the fuel cell controller controls the output of the fuel cell to be larger than the reference output when the remaining capacity of the secondary battery decreases after the start of the charging control mode.

7. The battery system control device according to claim 1, wherein

the control unit is capable of executing a power supply control mode for supplying power discharged by the secondary battery to the load, and

the fuel cell controller supplies the power generated by the fuel cell to the load when the output of the secondary battery is insufficient with respect to a request command value during the execution of the power supply control mode.

8. The battery system control device according to claim 2, wherein

the control unit is capable of executing a power supply control mode for supplying power discharged by the secondary battery to the load, and

the fuel cell controller supplies the power generated by the fuel cell to the load when the output of the secondary battery is insufficient with respect to a request command value during the execution of the power supply control mode.

9. The battery system control device according to claim 3, wherein

the control unit is capable of executing a power supply control mode for supplying power discharged by the secondary battery to the load, and

the fuel cell controller supplies the power generated by the fuel cell to the load when the output of the secondary battery is insufficient with respect to a request command value during the execution of the power supply control mode.

10. The battery system control device according to claim 4, wherein

the control unit is capable of executing a power supply control mode for supplying power discharged by the secondary battery to the load, and

the fuel cell controller supplies the power generated by the fuel cell to the load when the output of the secondary battery is insufficient with respect to a request command value during the execution of the power supply control mode.

11. The battery system control device according to claim 1, wherein

the load includes a drive motor capable of outputting a power for driving a drive wheel of an electric vehicle.

12. The battery system control device according to claim 2, wherein

the load includes a drive motor capable of outputting a power for driving a drive wheel of an electric vehicle.

13. The battery system control device according to claim 3, wherein

the load includes a drive motor capable of outputting a power for driving a drive wheel of an electric vehicle.

14. The battery system control device according to claim 4, wherein

the load includes a drive motor capable of outputting a power for driving a drive wheel of an electric vehicle.

15. A battery system, comprising:

a load;

a secondary battery that is connected to a load via a first power converter capable of converting a voltage by performing a switching operation, the secondary battery being capable of discharging power supplied to the load;

a fuel cell, being connected to the load, that is connected in parallel with the secondary battery and the first power converter, via a second power converter capable of converting a voltage by performing a switching operation, the fuel cell being capable of generating electric power of a low voltage as compared with a voltage of the secondary battery, and

a control device capable of executing a charging control mode for charging the secondary battery using the generated power from the fuel cell, wherein

the control unit comprises;

a fuel cell controller configured to step up the electric power generated by the fuel cell to a voltage that is chargeable by the secondary battery, and supply the stepped-up electric power to the load side of the second power converter by causing the second power converter to perform the switching operation during execution of the charging control mode; and

a secondary battery controller configured to directly connect the load side of the first power converter and the secondary battery by stopping the switching operation of the first power converter during the execution of the charging control mode.