CONTROL DEVICE AND CONTROL METHOD FOR ELECTRIC SYSTEM

• US 20100127669A1
• Filed: 06/10/2008
• Published: 05/27/2010
• Est. Priority Date: 06/11/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Jidoshokki (Toyota Motor Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Iida, Takahide
• Granted Patent: US 8,183,837 B2
• Time in Patent Office: Days
• US Class Current: 320/162
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

In an electric system including a first converter and a second converter connected in parallel, an ECU executes a program including a step of selecting a charging mode for a first battery pack connected to the first converter and a charging mode for a second battery pack connected to the second converter, and a step of controlling a charger connected to the first battery pack, the first converter and the second converter to charge the first battery pack and the second battery pack in the selected charging modes.

Claims

1. A control device for an electric system, comprising:

a first converter for varying a voltage;

a second converter connected in parallel to said first converter for varying a voltage;

a first power storage mechanism connected to said first converter for storing electric power;

a second power storage mechanism connected to said second converter for storing electric power;

a charger connected to said first power storage mechanism to supply electric power; and

an operation unit, wherein

said operation unit selects a charging mode for said first power storage mechanism, selects a charging mode for said second power storage mechanism, and controls said charger, said first converter and said second converter to charge at least any one of said first power storage mechanism and said second power storage mechanism in the selected mode.

2. The control device for an electric system according to claim 1, wherein

said operation unit controls said first converter and said second converter to charge said second power storage mechanism in the selected mode, and controls said charger to charge said first power storage mechanism in the selected mode.

3. The control device for an electric system according to claim 2, wherein

said operation unit controls said charger to charge said first power storage mechanism in the selected mode by outputting a current that is a sum of a current supplied to said first power storage mechanism and a current supplied to said second power storage mechanism.

4. The control device for an electric system according to claim 1, wherein

said operation unit selects either a mode of maintaining electric power to be charged into said first power storage mechanism constant or a mode of maintaining a current to be charged into said first power storage mechanism constant, and

selects either a mode of maintaining electric power to be charged into said second power storage mechanism constant or a mode of maintaining a current to be charged into said second power storage mechanism constant.

5. The control device for an electric system according to claim 4, wherein

said operation unit selects the mode of maintaining the electric power to be charged into said first power storage mechanism constant when a state of charge of said first power storage mechanism is lower than a threshold value, and selects the mode of maintaining the current to be charged into said first power storage mechanism constant when the state of charge of said first power storage mechanism is higher than the threshold value, and

said operation unit selects the mode of maintaining the electric power to be charged into said second power storage mechanism constant when a state of charge of said second power storage mechanism is lower than the threshold value, and selects the mode of maintaining the current to be charged into said second power storage mechanism constant when the state of charge of said second power storage mechanism is higher than the threshold value.

6. The control device for an electric system according to claim 1, wherein

when a target value of a current charged into said second power storage mechanism is lower than a minimum value of a current output from said second converter, said operation unit controls said second converter to output a current intermittently.

7. The control device for an electric system according to claim 1, wherein

said operation unit controls said charger, said first converter and said second converter to charge said first power storage mechanism and said second power storage mechanism simultaneously in charging modes different between said first power storage mechanism and said second power storage mechanism.

8. A control method for an electric system including a first converter for varying a voltage, a second converter connected in parallel to said first converter for varying a voltage, a first power storage mechanism connected to said first converter for storing electric power, a second power storage mechanism connected to said second converter for storing electric power, and a charger connected to said first power storage mechanism to supply electric power, comprising the steps of:

selecting a charging mode for said first power storage mechanism;

selecting a charging mode for said second power storage mechanism; and

controlling said charger, said first converter and said second converter to charge at least any one of said first power storage mechanism and said second power storage mechanism in the selected mode.

9. The control method for an electric system according to claim 8, wherein

said step of controlling said charger, said first converter and said second converter includes the steps of

controlling said first converter and said second converter to charge said second power storage mechanism in the selected mode, and

controlling said charger to charge said first power storage mechanism in the selected mode.

10. The control method for an electric system according to claim 9, wherein

said step of controlling said charger includes the step of controlling said charger to charge said first power storage mechanism in the selected mode by outputting a current that is a sum of a current supplied to said first power storage mechanism and a current supplied to said second power storage mechanism.

11. The control method for an electric system according to claim 8, wherein

said step of selecting a charging mode for said first power storage mechanism includes the step of selecting either a mode of maintaining electric power to be charged into said first power storage mechanism constant or a mode of maintaining a current to be charged into said first power storage mechanism constant, and

said step of selecting a charging mode for said second power storage mechanism includes the step of selecting either a mode of maintaining electric power to be charged into said second power storage mechanism constant or a mode of maintaining a current to be charged into said second power storage mechanism constant.

12. The control method for an electric system according to claim 11, wherein

said step of selecting either a mode of maintaining electric power to be charged into said first power storage mechanism constant or a mode of maintaining a current to be charged into said first power storage mechanism constant includes the step of selecting the mode of maintaining the electric power to be charged into said first power storage mechanism constant when a state of charge of said first power storage mechanism is lower than a threshold value, and selecting the mode of maintaining the current to be charged into said first power storage mechanism constant when the state of charge of said first power storage mechanism is higher than the threshold value, and

said step of selecting either a mode of maintaining electric power to be charged into said second power storage mechanism constant or a mode of maintaining a current to be charged into said second power storage mechanism constant includes the step of selecting the mode of maintaining the electric power to be charged into said second power storage mechanism constant when a state of charge of said second power storage mechanism is lower than the threshold value, and selecting the mode of maintaining the current to be charged into said second power storage mechanism constant when the state of charge of said second power storage mechanism is higher than the threshold value.

13. The control method for an electric system according to claim 8, further comprising the step of:

controlling, when a target value of a current charged into said second power storage mechanism is lower than a minimum value of a current output from said second converter, said second converter to output a current intermittently.

14. The control method for an electric system according to claim 8, wherein

said step of controlling said charger, said first converter and said second converter includes the step of controlling said charger, said first converter and said second converter to charge said first power storage mechanism and said second power storage mechanism simultaneously in charging modes different between said first power storage mechanism and said second power storage mechanism.

15. A control device for an electric system, comprising:

a first converter for varying a voltage;

a second converter connected in parallel to said first converter for varying a voltage;

a first power storage mechanism connected to said first converter for storing electric power;

a second power storage mechanism connected to said second converter for storing electric power;

a charger connected to said first power storage mechanism to supply electric power;

first selection means for selecting a charging mode for said first power storage mechanism;

second selection means for selecting a charging mode for said second power storage mechanism; and

control means for controlling said charger, said first converter and said second converter to charge at least any one of said first power storage mechanism and said second power storage mechanism in the selected mode.

16. The control device for an electric system according to claim 15, wherein

said control means includes

means for controlling said first converter and said second converter to charge said second power storage mechanism in the selected mode, and

charger control means for controlling said charger to charge said first power storage mechanism in the selected mode.

17. The control device for an electric system according to claim 16, wherein

said charger control means includes means for controlling said charger to charge said first power storage mechanism in the selected mode by outputting a current that is a sum of a current supplied to said first power storage mechanism and a current supplied to said second power storage mechanism.

18. The control device for an electric system according to claim 15, wherein

said first selection means includes first mode selection means for selecting either a mode of maintaining electric power to be charged into said first power storage mechanism constant or a mode of maintaining a current to be charged into said first power storage mechanism constant, and

said second selection means includes second mode selection means for selecting either a mode of maintaining electric power to be charged into said second power storage mechanism constant or a mode of maintaining a current to be charged into said second power storage mechanism constant.

19. The control device for an electric system according to claim 18, wherein

said first mode selection means includes means for selecting the mode of maintaining the electric power to be charged into said first power storage mechanism constant when a state of charge of said first power storage mechanism is lower than a threshold value, and selecting the mode of maintaining the current to be charged into said first power storage mechanism constant when the state of charge of said first power storage mechanism is higher than the threshold value, and

said second mode selection means includes means for selecting the mode of maintaining the electric power to be charged into said second power storage mechanism constant when a state of charge of said second power storage mechanism is lower than the threshold value, and selecting the mode of maintaining the current to be charged into said second power storage mechanism constant when the state of charge of said second power storage mechanism is higher than the threshold value.

20. The control device for an electric system according to claim 15, further comprising means for controlling, when a target value of a current charged into said second power storage mechanism is lower than a minimum value of a current output from said second converter, said converter to output a current intermittently.

21. The control device for an electric system according to claim 15, wherein

said control means includes means for controlling said charger, said first converter and said second converter to charge said first power storage mechanism and said second power storage mechanism simultaneously in charging modes different between said first power storage mechanism and said second power storage mechanism.