POWER SUPPLY SYSTEM AND VEHICLE INCLUDING THE SAME, AND METHOD OF CONTROLLING POWER SUPPLY SYSTEM

• US 20100100264A1
• Filed: 10/21/2009
• Published: 04/22/2010
• Est. Priority Date: 10/21/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kato, Norihiko
• Granted Patent: US 7,933,694 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A CD mode electric power allocation ratio calculation unit calculates an electric power allocation ratio between a first power storage device and a power storage device connected to a second converter by means of a switching device, to be used during a CD mode, based on a remaining electric power amount of each power storage device. A CS mode electric power allocation ratio calculation unit calculates a deviation amount between SOC of each of the first power storage device and the power storage device connected to the second converter and a target value thereof, and calculates an electric power allocation ratio to be used during a CS mode, based on the calculated deviation amount.

Claims

1. A power supply system mounted on a vehicle capable of running while switching between a first running mode of running using electric power stored for running without maintaining said electric power and a second running mode of running while maintaining said electric power at a prescribed target, comprising:

a power line for supplying and receiving electric power between a drive force generation portion for generating drive force for running upon receiving electric power from the power supply system and the power supply system;

first and second converters connected in parallel to said power line;

a first rechargeable power storage device connected to said first converter;

a plurality of second rechargeable power storage devices;

a switching device provided between said plurality of second power storage devices and said second converter, configured to connect any one of said plurality of second power storage devices to said second converter in accordance with a provided instruction; and

a control device for controlling said first and second converters and said switching device, and

said control device including

a switching control unit for generating said instruction for sequentially switching for use said plurality of second power storage devices such that, when a state quantity indicating a charged state of the second power storage device connected to said second converter is lower than a predetermined value, a remaining second power storage device of which state quantity is not lower than said predetermined value is connected to said second converter, and outputting said instruction to said switching device,

a first electric power allocation ratio calculation unit for calculating, based on a remaining electric power amount of each of said first power storage device and said plurality of second power storage devices, a first electric power allocation ratio indicating a ratio of allocation of charge and discharge electric power between said first power storage device and the second power storage device connected to said second converter by means of said switching device, to be used during said first running mode,

a second electric power allocation ratio calculation unit for calculating, based on a difference between said state quantity in each of said first power storage device and the second power storage device connected to said second converter by means of said switching device and a target value thereof, a second electric power allocation ratio indicating a ratio of allocation of charge and discharge electric power between said first power storage device and the second power storage device connected to said second converter, to be used during said second running mode, and

a converter control unit for controlling said first and second converters in accordance with said first electric power allocation ratio during said first running mode and controlling said first and second converters in accordance with said second electric power allocation ratio during said second running mode.

2. The power supply system according to claim 1, wherein

said target value of said first power storage device is set to said state quantity of said first power storage device attained when transition from said first running mode to said second running mode is made, and

said target value of the second power storage device connected to said second converter by means of said switching device is set to said state quantity of said second power storage device attained when transition from said first running mode to said second running mode is made.

3. The power supply system according to claim 1, wherein

said second electric power allocation ratio calculation unit calculates, when a first value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a positive value and a second value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a positive value,

said second electric power allocation ratio such that said first power storage device and the second power storage device connected to said second converter discharge in accordance with a ratio between said first value and said second value when electric power is supplied from the power supply system to said drive force generation portion, and

said second electric power allocation ratio such that said first power storage device and the second power storage device connected to said second converter are charged in accordance with an inverse ratio between said first value and said second value when electric power is supplied from said drive force generation portion to the power supply system.

4. The power supply system according to claim 1, wherein

said second electric power allocation ratio calculation unit calculates, when a first value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a negative value and a second value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a negative value,

said second electric power allocation ratio such that said first power storage device and the second power storage device connected to said second converter are charged in accordance with a ratio between said first value and said second value when electric power is supplied from said drive force generation portion to the power supply system, and

said second electric power allocation ratio such that said first power storage device and the second power storage device connected to said second converter discharge in accordance with an inverse ratio between said first value and said second value when electric power is supplied from the power supply system to said drive force generation portion.

5. The power supply system according to claim 1, wherein

said second electric power allocation ratio calculation unit calculates, when a value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a positive value and a value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a negative value,

said second electric power allocation ratio such that said first power storage device alone discharges when electric power is supplied from the power supply system to said drive force generation portion, and

said second electric power allocation ratio such that the second power storage device alone connected to said second converter is charged when electric power is supplied from said drive force generation portion to the power supply system.

6. The power supply system according to claim 1, wherein

said second electric power allocation ratio calculation unit calculates, when a value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a negative value and a value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a positive value,

said second electric power allocation ratio such that said second power storage device alone connected to said second converter discharges when electric power is supplied from the power supply system to said drive force generation portion, and

said second electric power allocation ratio such that said first power storage device alone is charged when electric power is supplied from said drive force generation portion to the power supply system.

7. The power supply system according to claim 1, wherein

said converter control unit includes

a first control unit for controlling said first converter such that a voltage on said power line is adjusted to a prescribed target voltage, and

a second control unit for controlling said second converter such that charge and discharge of the second power storage device connected to said second converter is adjusted to a prescribed target amount.

8. The power supply system according to claim 1, wherein

said switching device includes a plurality of relays connected between respective ones of said plurality of second power storage devices and said second converter.

9. The power supply system according to claim 1, further comprising a charger for charging said first power storage device and said plurality of second power storage devices upon receiving electric power from a power supply outside the vehicle.

10. A vehicle, comprising:

the power supply system according to claim 1; and

a drive force generation portion for generating drive force of the vehicle upon receiving electric power from said power supply system.

11. A method of controlling a power supply system mounted on a vehicle capable of running while switching between a first running mode of running using electric power stored for running without maintaining said electric power and a second running mode of running while maintaining said electric power at a prescribed target,

said power supply system including

a power line for supplying and receiving electric power between a drive force generation portion for generating drive force for running upon receiving electric power from the power supply system and the power supply system,

first and second converters connected in parallel to said power line,

a first rechargeable power storage device connected to said first converter,

a plurality of second rechargeable power storage devices, and

a switching device provided between said plurality of second power storage devices and said second converter, configured to connect any of said plurality of second power storage devices to said second converter in accordance with a provided instruction,

the method comprising the steps of:

controlling said switching device such that, when a state quantity indicating a charged state of the second power storage device connected to said second converter is lower than a predetermined value, a remaining second power storage device of which state quantity is not lower than said predetermined value is connected to said second converter;

calculating, based on a remaining electric power amount of each of said first power storage device and said plurality of second power storage devices, a first electric power allocation ratio indicating a ratio of allocation of charge and discharge electric power between said first power storage device and the second power storage device connected to said second converter by means of said switching device, to be used during said first running mode;

calculating, based on a difference between said state quantity in each of said first power storage device and the second power storage device connected to said second converter by means of said switching device and a target value thereof, a second electric power allocation ratio indicating a ratio of allocation of charge and discharge electric power between said first power storage device and the second power storage device connected to said second converter, to be used during said second running mode; and

controlling said first and second converters in accordance with said first electric power allocation ratio during said first running mode and controlling said first and second converters in accordance with said second electric power allocation ratio during said second running mode.

12. The method of controlling a power supply system according to claim 11, wherein

said target value of said first power storage device is set to said state quantity of said first power storage device attained when transition from said first running mode to said second running mode is made, and

said target value of the second power storage device connected to said second converter by means of said switching device is set to said state quantity of said second power storage device attained when transition from said first running mode to said second running mode is made.

13. The method of controlling a power supply system according to claim 11, wherein

in said step of calculating a second electric power allocation ratio, when a first value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a positive value and a second value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a positive value,

said second electric power allocation ratio is calculated such that said first power storage device and the second power storage device connected to said second converter discharge in accordance with a ratio between said first value and said second value when electric power is supplied from said power supply system to said drive force generation portion, and

said second electric power allocation ratio is calculated such that said first power storage device and the second power storage device connected to said second converter are charged in accordance with an inverse ratio between said first value and said second value when electric power is supplied from said drive force generation portion to said power supply system.

14. The method of controlling a power supply system according to claim 11, wherein

in said step of calculating a second electric power allocation ratio, when a first value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a negative value and a second value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a negative value,

said second electric power allocation ratio is calculated such that said first power storage device and the second power storage device connected to said second converter are charged in accordance with a ratio between said first value and said second value when electric power is supplied from said drive force generation portion to said power supply system, and

said second electric power allocation ratio is calculated such that said first power storage device and the second power storage device connected to said second converter discharge in accordance with an inverse ratio between said first value and said second value when electric power is supplied from said power supply system to said drive force generation portion.

15. The method of controlling a power supply system according to claim 11, wherein

in said step of calculating a second electric power allocation ratio, when a value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a positive value and a value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a negative value,

said second electric power allocation ratio is calculated such that said first power storage device alone discharges when electric power is supplied from said power supply system to said drive force generation portion, and

said second electric power allocation ratio is calculated such that the second power storage device alone connected to said second converter is charged when electric power is supplied from said drive force generation portion to said power supply system.

16. The method of controlling a power supply system according to claim 11, wherein

in said step of calculating a second electric power allocation ratio, when a value obtained by subtracting the target value of said state quantity of said first power storage device from said state quantity of said first power storage device has a negative value and a value obtained by subtracting the target value of said state quantity of the second power storage device connected to said second converter by means of said switching device from said state quantity of the second power storage device has a positive value,

said second electric power allocation ratio is calculated such that said second power storage device alone connected to said second converter discharges when electric power is supplied from said power supply system to said drive force generation portion, and

said second electric power allocation ratio is calculated such that said first power storage device alone is charged when electric power is supplied from said drive force generation portion to said power supply system.

17. The method of controlling a power supply system according to claim 11, wherein

in said step of controlling said first and second converters, said first converter is controlled such that a voltage on said power line is adjusted to a prescribed target voltage, and said second converter is controlled such that charge and discharge of the second power storage device connected to said second converter is adjusted to a prescribed target amount.