Fuel cell apparatus and method of controlling fuel cell apparatus

• US 6,893,757 B2
• Filed: 01/23/2002
• Issued: 05/17/2005
• Est. Priority Date: 01/26/2001
• Status: Expired due to Fees

• Current Assignee: Kabushikikaisha Equos Research
• Original Assignee: Kabushikikaisha Equos Research
• Inventors: Kato, Kenji
• Primary Examiner(s): Ryan, Patrick Joseph
• Assistant Examiner(s): ANTHONY, JULIAN
• Application Number:
  US10/052,408
• Publication Number:
  US 20020102447A1
• Time in Patent Office: 1,210 Days
• Field of Search: 429/22, 429/23, 429/25, 429/38, 429/39
• US Class Current: 429/430
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 10/4264 with capacitors
• 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 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04574 Current
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04597 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• 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 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A fuel cell apparatus includes a fuel cell connected directly to a load. An electricity accumulation circuit including an electricity accumulator is connected in parallel to the fuel cell. The electricity accumulator supplies electric power to the load when electric power supplied by the fuel cell is less than electric power that the load requires. The electricity accumulator is charged by regenerative power generated at the load and electric power output from the fuel cell. The fuel cell outputs electric power within a predetermined range.

Claims

1. A fuel cell apparatus comprising:

a fuel cell connected to a load;

an electricity accumulator connected in parallel to said fuel cell;

a step-up circuit provided between said electricity accumulator and said load, for increasing voltage output from said electricity accumulator; and

a control circuit for causing said step-up circuit to operate, when electric power that said load requires is greater than electric power that said fuel cell supplies, so that said electricity accumulator outputs electric power corresponding to a difference between the supplied electric power and the required electric power, to thereby prevent said fuel cell from outputting electric power out of a predetermined range.

2. A fuel cell apparatus according to claim 1, wherein said load is a drive control unit for a drive motor which drives the vehicle.

3. A fuel cell apparatus according to claim 1, wherein said fuel cell outputs electricity in such a manner that output voltage does not become lower than the lowest generatable voltage, output current does not exceed the maximum generatable current, and output power does not exceed the maximum output power.

4. A fuel cell apparatus according to claim 1, wherein said electricity accumulator outputs electricity when the electric power that said load requires exceeds the maximum output power of said fuel cell.

5. A fuel cell apparatus according to claim 1, wherein said electricity accumulator outputs electricity when output voltage of said fuel cell becomes lower than the lowest generatable voltage, when output current of said fuel cell exceeds the maximum generatable current, or when output power of said fuel cell exceeds the maximum output power.

6. A fuel cell apparatus according to claim 1, wherein fuel gas is supplied from a fuel storage unit to said fuel cell at constant pressure.

7. A fuel cell apparatus according to claim 6, wherein the fuel gas is supplied in such a manner that the pressure of the fuel gas becomes constant within grooves of fuel electrodes of said fuel cell.

8. A fuel cell apparatus according to claim 6, wherein said line includes a fuel supply line and a fuel discharge line;

a fuel supply solenoid valve is disposed in said fuel supply line; and

a fuel discharge solenoid valve is disposed in said fuel discharge line, wherein said fuel supply solenoid valve and said fuel discharge solenoid valve are turned on and off in order to regulate the pressure of the fuel gas.

9. A fuel cell apparatus according to claim 6, wherein a fuel pressure regulation valve is disposed in said line and is operated in order to regulate the pressure of the fuel gas.

10. A fuel cell apparatus according to claim 1, wherein said fuel cell apparatus further comprises a fuel supply apparatus for supply fuel gas to said fuel cell;

said fuel supply apparatus comprising a fuel storage unit, a supply line extending from said fuel storage unit to said fuel cell, and a valve disposed in said line, wherein said valve is operated in such a manner that the fuel gas is supplied to said fuel cell at constant pressure.

11. A fuel cell apparatus comprising a fuel cell, a load connected to an output terminal of said fuel cell, and an electricity accumulation circuit connected in parallel to said fuel cell with respect to said load, wherein said electricity accumulation circuit comprises:

an electricity accumulator;

a step-up circuit for increasing voltage output from said electricity accumulator to supply electric power to said load;

a charging circuit for supplying electric power output from said fuel cell to said electricity accumulator to charge said electricity accumulator; and

a traveling state detector for detecting a traveling state of a vehicle, wherein

said step-up circuit is operated in accordance with the traveling state of the vehicle as detected by said traveling state detector so that voltage output from said fuel cell is within a predetermined range, to thereby supply electric power of said electricity accumulator to said load.

12. A fuel cell apparatus comprising a fuel cell connected to a load, an electricity accumulation circuit connected in parallel to said fuel cell with respect to said load, and a diode element disposed for preventing supply of electric power from said load or said electricity accumulation circuit to said fuel cell, wherein said electricity accumulation circuit comprises:

a switching element for charging and a switching element for step-up connected in series;

an electricity accumulator connected in parallel to said switching element for step-up via a reactor; and

a traveling state detector for detecting a traveling state of a vehicle, wherein

said switching element for step-up is operated in accordance with the traveling state of the vehicle as detected by said traveling state detector so that voltage output from said fuel cell is within a predetermined range, to thereby supply electric power of said electricity accumulator to said load.