DC power supply using fuel cell

• US 20020038732A1
• Filed: 10/03/2001
• Published: 04/04/2002
• Est. Priority Date: 10/04/2000
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ishikawa, Tetsuhiro, Sugiura, Hiroshi, Watanabe, Nobuo, Manabe, Kouta
• Granted Patent: US 6,920,948 B2
• Time in Patent Office: Days
• US Class Current: 180/65.2
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/34 by heating
• 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 8/04388 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04395 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04626 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• 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 power supply system includes a fuel cell and a battery connected in parallel. A DC-DC converter is connected to the battery. A maximum output ratio of the fuel cell and the battery is set to be in a range where the output of the fuel cell is within 65 to 80% of the total output. Accordingly, electric power loss owing to conversion performed by the DC-DC converter is reduced to achieve a high energy efficiency.

Claims

1. A direct current power supply system for a vehicle, comprising:

a pair of terminals that generate an electric power;

a fuel cell connected to the terminals;

a DC/DC converter connected to the terminals; and

an electric power storage unit that is connected to the terminals via the DC-DC converter in parallel with the fuel cell, the electric power storage unit being able to be charged and discharged.

2. A direct current power supply system according to claim 1, wherein a maximum output power of the fuel cell is greater than a maximum output power of the electric power storage unit.

3. A direct current power supply system according to claim 1, further comprising fuel-cell accessories that operate to drive the fuel cell, wherein at least a part of the fuel-cell accessories is directly connected to the electric power storage unit such that the at least a part of the fuel-cell accessories can be driven by the electric power storage unit serving as a power supply.

4. A direct current power supply system according to claim 1, further comprising a controller that controls an output voltage of the DC/DC converter to be substantially equal to an output voltage of the fuel cell.

5. A direct current power supply system according to claim 1, further comprising a controller that controls an output voltage of the DC/DC converter to a predetermined voltage at which the electric power storage unit is allowed to be charged by one of the fuel cell and the terminals.

6. A direct current power supply system according to claim 1, wherein the electric power storage unit comprises a secondary battery.

7. A vehicle comprising:

a motor serving as a driving power source,

a direct current power supply unit that supplies an electric power to the motor, and

a drive circuit that drives the motor by the electric power, wherein the direct current power supply unit comprises;

a pair of terminals that generate an electric power;

a fuel cell connected to the terminals;

a DC/DC converter connected to the terminals; and

an electric power storage unit that is connected to the terminals via the DC-DC converter in parallel with the fuel cell, the electric power storage unit being able to be charged and discharged.

8. A vehicle according to claim 7, wherein a maximum output power of the fuel cell is greater than a maximum output power of the electric power storage unit.

9. A vehicle according to claim 7, further comprising vehicle accessories that operate to drive the vehicle, wherein at least a part of the vehicle accessories is directly connected to the electric power storage unit such that the at least one of the vehicle accessories can be driven by the electric power storage unit serving as a power supply.

10. A vehicle according to claim 7, further comprising fuel-cell accessories that operate to drive the fuel cell, wherein at least a part of the fuel-cell accessories is directly connected to the electric power storage unit such that the at least a part of the fuel-cell accessories can be driven by the electric power storage unit serving as a power supply.

11. A vehicle according to claim 7, further comprising a controller that controls an output voltage of the DC/DC converter to be substantially equal to an output voltage of the fuel cell.

12. A vehicle according to claim 7, further comprising a controller that controls an output voltage of the DC/DC converter to a predetermined voltage at which the electric power storage unit is allowed to be charged by one of the fuel cell and the terminals.

13. A vehicle according to claim 7, wherein the electric power storage unit comprises a secondary battery.

14. A method for supplying a direct current from a fuel cell and an electric power storage unit that can be charged and discharged to output terminals, which are connected in parallel with the output terminals, the method comprising:

(a) operating the fuel cell to generate a predetermined voltage; and

(b) converting a voltage generated by the electric power accumulating unit by using the DC-DC converter to a voltage equal to the predetermined voltage generated by the fuel cell and applying the converted voltage to the terminals.