Fuel cell system including controller to prevent over-discharge of battery and lowering in drivability upon recovering from idle stop

Patent metadata

Field	Value
Publication number	US-9640812-B2
Application number	US-201214118024-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	May 18, 2011
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

The fuel cell system of the present invention comprises: an electric motor, a fuel cell stack, a fuel supply unit, and a controller that controls a power-plant including the fuel cell stack and the fuel supply unit. The controller comprises further: a stack output-response request computing unit to compute a stack output-response request requested for the fuel cell stack; a stack voltage setup unit during idle-stop to set up a lower limit of stack setup-voltage during idle-stop that is set up as a stack voltage during execution of idle-stop so as to be higher as the stack output-response request is larger, and so as to be lower as the request is smaller; and an operation unit of recovering a stack voltage during idle-stop to execute a recovery operation when an actual stack voltage becomes, during execution of idle-stop, lower than the lower limit of stack setup-voltage during idle-stop.

First claim

The invention claimed is:

1. A control method for a fuel cell system, including a driving unit configured to run a mobile body by supplying an electric power, a fuel cell stack configured to supply an electric power to the driving unit for running, a fuel supply unit configured to supply fuel necessary for electric power generation of the fuel cell stack, comprising:
computing a stack output-response request, the stack output-response request being an electric power response required from the fuel cell stack to return from an idle-stop;
setting up a lower limit of a stack setup-voltage during the idle-stop as a stack voltage during execution of the idle-stop that becomes higher as the stack output-response request becomes larger and becomes lower as the stack output-response request becomes smaller; and
executing a recovery operation in which the fuel or air is supplied when an actual voltage of the fuel cell stack becomes lower than the lower limit of the stack setup-voltage during the idle-stop.

2. A fuel cell system, comprising:
a driving unit configured to run a mobile body by supplying an electric power;
a fuel cell stack configured to supply an electric power to the driving unit for running;
a fuel supply unit configured to supply fuel necessary for electric power generation of the fuel cell stack; and
a controller configured to control a power-plant comprising the fuel cell stack and the fuel supply unit,
wherein,
the controller comprises:
a stack output-response request computing unit programmed to compute a stack output-response request, the stack output-response request being an electric power response required from the fuel cell stack to return from an idle-stop;
a stack voltage setup unit programmed to set up, during the idle-stop, a lower limit of a stack setup-voltage during the idle-stop that is set up as a stack voltage during execution of the idle-stop that becomes higher as the stack output-response request becomes larger and becomes lower as the stack output-response request becomes smaller; and
an operation unit of recovering a stack voltage during the idle-stop programmed to execute a recovery operation in which the fuel or air is supplied when an actual voltage of the fuel cell stack becomes lower than the lower limit of the stack setup-voltage during the idle-stop.

3. The fuel cell system according to claim 2 , further comprising:
a vehicle speed detecting device configured to detect a vehicle speed,
wherein,
the stack output-response request computing unit is programmed to compute a stack output-response request that becomes higher as the vehicle speed becomes higher.

4. The fuel cell system according to claim 2 , further comprising:
a battery's dischargeable output electric power detecting device configured to detect a battery's dischargeable output electric power,
wherein,
the stack output-response request computing unit is programmed to compute a stack output-response request that becomes higher as the battery's dischargeable output electric power becomes lower.

5. The fuel cell system according to claim 2 , further comprising:
a device configured to detect an output-response performance of the power-plant,
wherein,
the stack output-response request computing unit is programmed to compute a stack output-response request that becomes higher as the output-response performance of the power-plant becomes lower.

6. The fuel cell system according to claim 2 , further comprising:
an accessories electric power consumption detecting device adapted to detect an electric power consumed by accessories,
wherein,
the stack output-response request computing unit is programmed to compute a stack output-response request that becomes higher as the accessories electric power consumption becomes larger.

7. A fuel cell system, comprising:
a driving unit configured to run a mobile body by supplying an electric power;
a fuel cell stack configured to supply an electric power to the driving unit for running;
a fuel supply unit configured to supply fuel necessary for electric power generation of the fuel cell stack; and
stack output-response request computing means for computing a stack output-response request, the stack output-response request being an electric power response required from the fuel cell stack to return from an idle-stop;
stack voltage setup means for setting up, during the idle-stop, a lower limit of a stack setup-voltage during the idle-stop that is set up as a stack voltage during execution of the idle-stop that becomes higher as the stack output-response request becomes larger and becomes lower as the stack output-response request becomes smaller; and
operation means of recovering a stack voltage during idle-stop for executing a recovery operation in which the fuel or air is supplied when an actual voltage of the fuel cell stack becomes lower than the lower limit of the stack setup-voltage during the idle-stop.

Assignees

• Kumada Mitsunori
• Makino Shinichi
• Asai Yoshitomo
• Nissan Motor

Inventors

• Kumada Mitsunori
• Makino Shinichi
• Asai Yoshitomo

Classifications

• H01M8/0438

  Pressure; Ambient pressure; Flow · CPC title

• B60L2240/12

  Speed · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title

• Y02T90/34

  Cross-Sectional Technologies · mapped topic

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title