Fuel cell system

Patent metadata

Field	Value
Publication number	US-11450870-B2
Application number	US-202117326602-A
Country	US
Kind code	B2
Filing date	May 21, 2021
Priority date	May 29, 2020
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A fuel cell system includes: a fuel cell in which a plurality of cells is stacked; a cathode gas supply unit that supplies a cathode gas to the fuel cell; a voltage sensor that measures the voltage of the fuel cell; and a control unit that maintains the voltage of the fuel cell within a predetermined voltage range by controlling a supply amount of the cathode gas during low-load operation in which a load is lower than in normal operation. The control unit determines that there is a cross-leakage abnormality in the fuel cell when the supply amount of the cathode gas required to maintain the voltage of the fuel cell within the predetermined voltage range exceeds a predetermined criterial threshold value during the low-load operation.

First claim

What is claimed is:

1. A fuel cell system comprising:
a fuel cell in which a plurality of cells is stacked;
a cathode gas supply unit configured to supply a cathode gas to the fuel cell;
a voltage sensor configured to measure a voltage of the fuel cell; and
a control unit configured to maintain the voltage of the fuel cell within a predetermined range by controlling a supply amount of the cathode gas during low-load operation in which a load is lower than in normal operation, wherein
the control unit is configured to determine that there is a cross-leakage abnormality in the fuel cell when the supply amount of the cathode gas required to maintain the voltage of the fuel cell within the predetermined range exceeds a predetermined criterial threshold value during the low-load operation.

2. The fuel cell system according to claim 1 , wherein:
an upper-limit threshold value of the predetermined range is set to be smaller than an upper-limit voltage value at which an electrolyte membrane constituting a part of each of the plurality of cells is oxidized; and
a lower-limit threshold value of the predetermined range is set to be larger than a lower-limit voltage value at which the electrolyte membrane is reduced.

3. The fuel cell system according to claim 1 , wherein:
the cathode gas supply unit is a compressor that is provided in an air supply passage connected to the fuel cell; and
the supply amount of the cathode gas is calculated based on a command value for a flow rate of the cathode gas or a command value for a rotation speed of the compressor that is given by the control unit.

4. The fuel cell system according to claim 1 , wherein the control unit is configured to determine that there is a cross-leakage abnormality in the fuel cell when the supply amount of the cathode gas exceeds the predetermined criterial threshold value more than once during continuous low-load operation.

Assignees

• Toyota Motor Co Ltd
• Denso Corp

Inventors

• Kawahara Shuya
• Otsuka Shinobu

Classifications

• H01M8/1004 Primary

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/04089

  of gaseous reactants · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title

• H01M2250/20

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

• H01M8/0488

  of fuel cell stacks · CPC title