Power supply system, electric vehicle with power supply system mounted thereon, and method of regulating amount of fuel supply

• US 5,964,309 A
• Filed: 07/25/1997
• Issued: 10/12/1999
• Est. Priority Date: 07/26/1996
• Status: Expired due to Term

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Horiguchi, Munehisa, Kimura, Yoshio, Nonobe, Yasuhiro
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): JASMIN, LYNDA C
• Application Number:
  US08/900,712
• Time in Patent Office: 809 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.4, 180/65.5, 180/65.8, 701/22
• US Class Current: 180/65.8
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/31 for starting of fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/34 by heating
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/484 for measuring electrolyte level, electrolyte density or electrolyte conductivity
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: H01M 8/04567 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04604 Power, energy, capacity or load
• 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 8/04955 Shut-off or shut-down of fuel cells
• CPC Class Codes: H01M 8/241 with solid or matrix-supported electrolytes
• CPC Class Codes: H01M 8/2457 with both reactants being gaseous or vaporised
• 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 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 power supply system 10 with a stack of fuel cells 20 and a storage battery 30 includes a remaining charge monitor 42 for measuring the remaining charge of the storage battery 30. At the time of starting the power supply system 10, the remaining charge monitor 42 detects the remaining charge of the storage battery 30. The power supply system 10 estimates output electric current of the fuel cells 20 based on the observed remaining charge of the storage battery 30 and an amount of electric power required for auxiliary machinery 34, and supplies required amounts of gases to the fuel cells 20 based on the estimated output electric current.

Claims

1. A power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading, wherein said stack of fuel cells and said storage battery supply electric power to said loading, said power supply system comprising:

remaining charge detection means for detecting a remaining charge of said storage battery;

amount-of-loading detection means for detecting a total amount of said loading;

charge-discharge state estimation means for estimating a charge-discharge state of said storage battery, based on the results of detection by said remaining charge detection means and said amount-of-loading detection means;

amount-of-fuel supply determination means for determining a required amount of a fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated by said charge-discharge state estimation means; and

fuel supply means for supplying the required amount of said fuel determined by said amount-of-fuel supply determination means to said stack of fuel cells.

2. A power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading, wherein said stack of fuel cells and said storage battery supply electric power to said loading, said power supply system comprising:

remaining charge detection means for detecting a remaining charge of said storage battery;

charge-discharge state estimation means for, at the time of starting said power supply system, estimating a charge-discharge state of said storage battery, based on a predetermined amount of loading, which represents electric power consumed by machinery driven at the time of starting said power supply system, out of said loading and the result of detection by said remaining charge detection means;

amount-of-fuel supply determination means for, at least when said storage battery is in a charging condition, determining a required amount of a fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated by said charge-discharge state estimation means; and

fuel supply means for supplying the required amount of said fuel determined by said amount-of-fuel supply determination means to said stack of fuel cells.

3. An electric vehicle having a motor rotated by electrical energy and means for transmitting a rotational force of said motor to an axle, thereby producing a driving force for said vehicle,

said electric vehicle having a power supply system mounted thereon, said power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading comprising said motor, wherein said stack of fuel cells and said storage battery supply electric power to said loading, said power supply system comprising:

remaining charge detection means for detecting a remaining charge of said storage battery;

amount-of-loading detection means for detecting a total amount of said loading;

charge-discharge state estimation means for estimating a charge-discharge state of said storage battery, based on the results of detection by said remaining charge detection means and said amount-of-loading detection means;

amount-of-fuel supply determination means for determining a required amount of a fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated by said charge-discharge state estimation means; and

fuel supply means for supplying the required amount of said fuel determined by said amount-of-fuel supply determination means to said stack of fuel cells.

4. An electric vehicle having a motor rotated by electrical energy and means for transmitting a rotational force of said motor to an axle, thereby producing a driving force for said vehicle,

said electric vehicle having a power supply system mounted thereon, said power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading comprising said motor, wherein said stack of fuel cells and said storage battery supply electric power to said loading, said power supply system comprising:

remaining charge detection means for detecting a remaining charge of said storage battery;

charge-discharge state estimation means for, at the time of starting said power supply system, estimating a charge-discharge state of said storage battery, based on a predetermined amount of loading, which represents electric power consumed by machinery driven at the time of starting said power supply system, out of said loading and the result of detection by said remaining charge detection means;

amount-of-fuel supply determination means for, at least when said storage battery is in a charging condition, determining a required amount of a fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated by said charge-discharge state estimation means; and

fuel supply means for supplying the required amount of said fuel determined by said amount-of-fuel supply determination means to said stack of fuel cells.

5. In a power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading, wherein said stack of fuel cells and said storage battery supply electric power to said loading, a method of regulating an amount of a fuel supplied to said stack of fuel cells for power generation in said stack of fuel cells, said method comprising the steps of:

(a) detecting a remaining charge of said storage battery;

(b) detecting a total amount of said loading;

(c) estimating a charge-discharge state of said storage battery, based on the remaining charge detected in said step (a) and the total amount of said loading detected in said step (b);

(d) determining a required amount of said fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated in said step (c); and

(e) supplying the required amount of said fuel determined in said step (d) to said stack of fuel cells.

6. In a power supply system comprising a stack of fuel cells and a storage battery, which are connected parallel to each other and also to a loading, wherein said stack of fuel cells and said storage battery supply electric power to said loading, a method of regulating an amount of a fuel supplied to said stack of fuel cells for power generation in said stack of fuel cells, said method comprising the steps of:

(a) detecting a remaining charge of said storage battery;

(b) at the time of starting said power supply system, estimating a charge-discharge state of said storage battery, based on a predetermined amount of loading, which represents electric power consumed by machinery driven at the time of starting said power supply system, out of said loading and the remaining charge detected in said step (a);

(c) at least when said storage battery is in a charging condition, determining a required amount of said fuel for power generation in said stack of fuel cells, based on the charge-discharge state of said storage battery estimated in said step (b); and

(d) supplying the required amount of said fuel determined in said step (c) to said stack of fuel cells.