POWER SUPPLY SYSTEM, VEHICLE PROVIDED WITH THE SAME, POWER SUPPLY SYSTEM CONTROL METHOD AND COMPUTER-READABLE RECORDING MEDIUM BEARING PROGRAM FOR CAUSING COMPUTER TO CONTROL THE POWER SUPPLY SYSTEM

• US 20090183934A1
• Filed: 06/13/2007
• Published: 07/23/2009
• Est. Priority Date: 07/07/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ichikawa, Shinji, Ang, Wangleng, Oyobe, Hichirosai, Yoshida, Hiroshi, Sawada, Hiroki
• Granted Patent: US 8,297,391 B2
• Time in Patent Office: Days
• US Class Current: 180/65.265
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• 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
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

First and second converters are connected in parallel to positive and negative lines, respectively. When a required power is smaller than a reference value, an ECU controls the first and second converters such that one of the first and second converters operates and the other stops. When the required power is equal to or larger than the reference value, the ECU controls the first and second converters such that both the first and second converters operate.

Claims

1. A power supply system provided with a plurality of power storage devices, comprising:

a first voltage converting device arranged between a first power storage device and a load device for converting a voltage provided from said first power storage device and providing the converted voltage to said load device;

a second voltage converting device arranged between a second power storage device and said load device for converting a voltage provided from said second power storage device and providing the converted voltage to said load device; and

a control unit controlling said first and second voltage converting devices such that one of said first and second voltage converting devices operates and the other voltage converting device stops when a required power required of the power supply system is smaller than a reference value, and controlling said first and second voltage converting devices such that both of said first and second voltage converting devices operate when said required power is equal to or larger than said reference value.

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

when said required power is smaller than said reference value, said control unit stops the voltage converting device corresponding to one of said first and second power storage devices providing a lower output voltage than the other.

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

said reference value is determined based on a resistance loss in said first and second power storage devices and a switching loss in said first and second voltage converting devices.

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

said control unit changes said reference value such that said reference value increases as a temperature of said first and second power storage devices becomes high.

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

said control unit changes said reference value such that said reference value increases as a state of charge representing a charged state of said first and second power storage devices becomes high.

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

said control unit changes said reference value such that said reference value increases as a switching frequency of said first and second voltage converting devices becomes high.

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

one of said first and second power storage devices includes a secondary battery, and

the other of said first and second power storage devices includes a capacitor.

8. A vehicle comprising:

a plurality of power storage devices;

a power supply system;

a drive device supplied with an electric power from said power supply system;

an electric motor driven by said drive device; and

a wheel driven by said electric motor, wherein

said power supply system includes;

a first voltage converting device arranged between a first power storage device and said drive device for converting a voltage provided from said first power storage device and providing the converted voltage to said drive device;

a second voltage converting device arranged between a second power storage device and said drive device for converting a voltage provided from said second power storage device and providing the converted voltage to said drive device; and

a control unit controlling said first and second voltage converting devices such that one of said first and second voltage converting devices operates and the other voltage converting device stops when a required power required of said power supply system is smaller than a reference value, and controlling said first and second voltage converting devices such that both of said first and second voltage converting devices operate when said required power is equal to or larger than said reference value.

9. A method of controlling a power supply system provided with a plurality of power storage devices, wherein

said power supply system includes:

a first voltage converting device arranged between a first power storage device and a load device for converting a voltage provided from said first power storage device and providing the converted voltage to said load device; and

a second voltage converting device arranged between a second power storage device and said load device for converting a voltage provided from said second power storage device and providing the converted voltage to said load device, and said control method comprises;

a first step of comparing a required power required of said power supply system with a reference value;

a second step of controlling said first and second voltage converting devices such that one of said first and second voltage converting devices operates and the other voltage converting device stops, when said required power is smaller than the reference value; and

a third step of controlling said first and second voltage converting devices such that both of said first and second voltage converting devices operate, when said required power is equal to or larger than said reference value.

10. The method of controlling the power supply system according to claim 9, wherein

said second-step includes:

a first sub-step of comparing an output voltage of said first power storage device with an output voltage of said second power storage device,

a second sub-step of stopping said first voltage converting device when the output voltage of said first power storage-device is lower than the output voltage of said second power storage device, and

a third sub-step of stopping said second voltage converting device when the output voltage of said second power storage device is lower than the output voltage of said first power storage device.

11. The method of controlling the power supply system according to claim 9, wherein

said reference value is determined based on a resistance loss in said first and second power storage devices and a switching loss in said first and second voltage converting devices.

12. The method of controlling the power supply system according to claim 9, wherein

said reference value is set to increase as a temperature of said first and second power storage devices becomes high.

13. The method of controlling the power supply system according to claim 9, wherein

said reference value is set to increase as a state of charge indicating a charged state of said first and second power storage devices becomes high.

14. The method of controlling the power supply system according to claim 9, wherein

said reference value is set to increase as a switching frequency of said first and second voltage converting devices becomes high.

15. A computer-readable recording medium storing a program for causing a computer to control a. power supply system provided with a plurality of power storage devices, wherein

said power supply system includes:

a first voltage converting device arranged between a first power storage device and a load device for converting a voltage provided from said first power storage device and providing the converted voltage to said load device; and

a second voltage converting device arranged between a second power storage device and said load device for converting a voltage provided from said second power storage device and providing the converted voltage to said load device, and

said recording medium stores the program for causing said computer to execute;

a first step of comparing a required power required of said power supply system with a reference value;

a second step of controlling said first and second voltage converting devices such that one of said first and second voltage converting devices operates and the other voltage converting device stops, when said required power is smaller than the reference value; and

a third step of controlling said first and second voltage converting devices such that both of said first and second voltage converting devices operate, when said required power is equal to or larger than said reference value.