Fuel cell system

Patent metadata

Field	Value
Publication number	US-2020243878-A1
Application number	US-201916726352-A
Country	US
Kind code	A1
Filing date	Dec 24, 2019
Priority date	Jan 28, 2019
Publication date	Jul 30, 2020
Grant date	—

Abstract

A fuel cell system includes a fuel cell including a fuel electrode being supplied with fuel gas and an oxidant electrode being supplied with oxidant gas and generating electric power by causing the fuel gas and the oxidant gas to react with each other, a voltmeter measuring an output voltage of the fuel cell, an ammeter measuring an output current of the fuel cell, a restricting valve provided upstream and downstream of an oxidant electrode side of the fuel cell and being opened in a power generation state and being closed in a stopped state or under the oxygen consuming control, and a load control unit controlling a current value of an output current to be output by the fuel cell and, under the oxygen consuming control, controlling the output voltage of the fuel cell such that the output current reduces as the output voltage of the fuel cell increases.

First claim

What is claimed is:

1 . A fuel cell system that executes oxygen consuming control for consuming oxygen remaining in a fuel cell when the fuel cell is shifted from a power generation state to a stopped state, the fuel cell system comprising:
the fuel cell including a fuel electrode configured to be supplied with fuel gas and an oxidant electrode configured to be supplied with oxidant gas, the fuel cell being configured to generate electric power by causing the fuel gas and the oxidant gas to react with each other; a voltmeter configured to measure an output voltage of the fuel cell; an ammeter configured to measure an output current of the fuel cell; a restricting valve provided upstream and downstream of an oxidant electrode side of the fuel cell, the restricting valve being configured to be opened in the power generation state and be closed in the stopped state or under the oxygen consuming control; and a load control unit configured to control a current value of the output current that the fuel cell outputs, the load control unit being configured to, under the oxygen consuming control, control the output current of the fuel cell such that the output current reduces as the output voltage of the fuel cell increases.

2 . The fuel cell system according to claim 1 , further comprising:
a secondary battery; and a load wire configured to transmit electric power, which is output by the fuel cell or the secondary battery, to a load, wherein the load control unit is configured to, under the oxygen consuming control, supply the secondary battery with electric power taken out from the fuel cell.

3 . The fuel cell system according to claim 2 , wherein:
the load control unit is configured to
acquire, from the secondary battery, information about an allowable electric power that indicates a chargeable electric power in the secondary battery,
calculate an output electric power of the fuel cell from the output voltage acquired from the voltmeter and the output current acquired from the ammeter, and
control the output current of the fuel cell based on an oxygen consuming current that is obtained by dividing a value, obtained by subtracting the output electric power from the allowable electric power, by the output voltage.

4 . The fuel cell system according to claim 3 , wherein the load control unit has a target current value in advance, the target current value is a target value of the output current to be output by the fuel cell under the oxygen consuming control, the load control unit is configured to control the output current of the fuel cell based on a current command value that is obtained by adding the oxygen consuming current to the target current value.

5 . The fuel cell system according to claim 1 , wherein, in the fuel cell, a plurality of cells is stacked to become a fuel cell stack and gas containing oxidant is supplied to the plurality of cells via a manifold extending through the fuel cell stack.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamori Keitaro
• Ogawa Tomoya
• Mori Hiroaki

Classifications

• H01M8/04544

  Voltage · CPC title

• H01M8/04231

  Purging of the reactants · CPC title

• H01M8/04228 Primary

  during shut-down · CPC title

• H01M8/04895

  Current · CPC title

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title