Fuel cell voltage generator

• US 5,714,874 A
• Filed: 01/15/1997
• Issued: 02/03/1998
• Est. Priority Date: 09/06/1993
• Status: Expired due to Fees

• Current Assignee: Imra Europe S.A.S. (Aisin Corp.)
• Original Assignee: Imra Europe S.A.S. (Aisin Corp.)
• Inventors: Bonnefoy, Pierre
• Primary Examiner(s): Krishnan, Aditya
• Application Number:
  US08/783,699
• Time in Patent Office: 384 Days
• Field of Search: 320/6, 320/2-5, 320/15-19, 320/31-33, 320/48-49, 323/299-304
• US Class Current: 323/299
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/04917 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04955 Shut-off or shut-down of fuel cells
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

The invention relates to a voltage generator including a fuel cell, a d.c. converter and a storage battery, the input terminals of the d.c. converter being connected to the fuel cell terminals and the output terminals of the d.c. converter being connected on the voltage generator terminals in parallel with those of the battery. A microprocessor regulates the maximum intensity value of the current going through the d.c. converter responsive to the voltage measured at the terminals of the fuel cell in order to maintain the voltage near a preset reference value.

Claims

1. A voltage generator having terminals to be connected to a current load, comprising:

a fuel cell for generating electrical energy to be used by the current load;

a d.c. converter having input terminals connected to terminals of the fuel cell and output terminals connected to the voltage generator terminals;

a storage battery having terminals connected to the voltage generator terminals in a parallel connection with the d.c. converter output terminals; and

control means for modifying a maximum intensity value of the current flowing through said d.c. converter in accordance with a voltage measured at the terminals of the fuel cell to keep said voltage within a predetermined range, at which a power output of the fuel cell is maximum.

2. A voltage generator having terminals to be connected to a current load, comprising:

a fuel cell for generating electrical energy to be used by the current load;

a d.c. converter having input terminals connected to terminals of the fuel cell and output terminals connected to the voltage generator terminals;

a storage battery having terminals connected to the voltage generator terminals in a parallel connection with the d.c. converter output terminals, the storage battery storing electrical energy which is in excess of that required by the current load and supplying additional electrical energy to the current load if the current load requires more electrical energy than that generated by the fuel cell; and

control means for modifying a maximum intensity value of the current flowing through said d.c. converter in accordance with a voltage measured at the terminals of the fuel cell to keep said voltage within a predetermined range.

3. A voltage generator according to claim 2, wherein the control means includes means for measuring the voltage at the terminals of the fuel cell, and wherein the control means respectively increments and decrements the maximum intensity value of the current following through the d.c. converter when the voltage measured at the terminals of the fuel cell is above and below said predetermined range.

4. A voltage generator according to claim 3, wherein said predetermined range corresponds to a voltage range at which a power output of the fuel cell is maximum.

5. A voltage generator having terminals to be connected to a current load, comprising:

a fuel cell for generating electrical energy to be used by the current load;

a d.c. converter having input terminals connected to terminals of the fuel cell and output terminals connected to the voltage generator terminals;

a storage battery having terminals connected to the voltage generator terminals in a parallel connection with the d.c. converter output terminals; and

control means for modifying a maximum intensity value of the current flowing through said d.c. converter in accordance with a voltage measured at the terminals of the fuel cell to continuously keep said voltage within a predetermined range, at which a power output of the fuel cell is maximum, said control means including means for measuring the voltage at the terminals of the fuel cell, and respectively incrementing and decrementing the maximum intensity value of the current flowing through the d.c. converter when the voltage measured at the terminals of the fuel cell is above and below said predetermined range.

6. A voltage generator having terminals to be connected to a current load, comprising:

a fuel cell for generating electrical energy to be used by the current load;

a d.c. converter having input terminals connected to terminals of the fuel cell and output terminals connected to the voltage generator terminals;

a storage battery having terminals connected to the voltage generator terminals in a parallel connection with the d.c. converter output terminals; and

control means for modifying a maximum intensity value of the current flowing through said d.c. converter in accordance with a voltage measured at the terminals of the fuel cell to continuously keep said voltage within a predetermined range, at which a power output of the fuel cell is maxium,

wherein said storage battery stores electrical energy which is in excess of that required by the current load and supplies additional electrical energy to the current load if the current load requires more electrical energy than that generated by the fuel cell.