Fuel cell system and control method thereof

Patent metadata

Field	Value
Publication number	US-10424799-B2
Application number	US-201514933388-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 14, 2014
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

An object is to suppress drying of a fuel cell during continuous operation with high load. There is provided a fuel cell system including a fuel cell. The fuel cell system comprises an impedance detector that is configured to detect an impedance of the fuel cell; and a current limiter that is configured to limit an output current of the fuel cell with a limiting rate. The current limiter changes the limiting rate, based on the detected impedance.

First claim

What is claimed is:

1. A fuel cell system including a fuel cell, the fuel cell system comprising
an impedance detector that is configured to detect an impedance of the fuel cell;
a temperature detector that is configured to detect temperature of the fuel cell; and
a current limiter that is programmed to limit an output current of the fuel cell with a limiting rate, wherein
the current limiter is programmed to change the limiting rate, based on the detected impedance and the detected temperature, wherein
when the detected temperature is less than or equal to a predetermined threshold, the current limiter is programmed to set the limiting rate at a fixed rate regardless of the detected impedance, and
when the detected temperature is greater than the predetermined threshold, the current limiter is programmed to set the limiting rate based on the detected impedance such that the limiting rate is
a first rate for the detected temperature in a case where the detected impedance is a first value, and
a second rate that is lower than the first rate for the same detected temperature in a case where the detected impedance is a second value that is higher than the first value.

2. The fuel cell system according to claim 1 ,
wherein when the detected temperature is equal to a second temperature that is higher than a first temperature, the current limiter is programmed to set a lower limiting rate than a limiting rate at the temperature equal to the first temperature under condition of a fixed impedance.

3. A control method of a fuel cell system including a fuel cell, the control method comprising
detecting an impedance of the fuel cell;
detecting temperature of the fuel cell;
limiting an output current of the fuel cell with a limiting rate; and
changing the limiting rate, based on the detected impedance and the detected temperature of the fuel cell, such that
when the detected temperature is less than or equal to a predetermined threshold, the limiting rate is set at a fixed rate regardless of the detected impedance, and
when the detected temperature is greater than the predetermined threshold, the limiting rate is set based on the detected impedance such that the limiting rate is
a first rate for the detected temperature in a case where the detected impedance is a first value, and
a second rate that is lower than the first rate for the same detected temperature in a case where the detected impedance is a second value that is higher than the first value.

4. The control method of the fuel cell system according to claim 3 ,
wherein when the detected temperature is equal to a second temperature that is higher than a first temperature, the changing the limiting rate sets a lower limiting rate than a limiting rate at the temperature equal to the first temperature under condition of a fixed impedance.

Assignees

• Toyota Motor Co Ltd

Inventors

• Imanishi Hiroyuki
• Maruo Tsuyoshi
• Yamada Takashi

Classifications

• H01M8/0491

  of fuel cell stacks · CPC title

• H01M8/04649

  of fuel cell stacks · CPC title

• H01M8/04641

  of the individual fuel cell · CPC title

• H01M8/04902 Primary

  of the individual fuel cell · CPC title

• H01M8/04992 Primary

  characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence · CPC title