# US 8,568,935 B2 · Method for managing fuel cell power increases using air flow feedback delay

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- Number: US 8,568,935 B2
- Document ID: US8568935B2
- Status: Granted
- Kind: B2
- Application number: 13/020,294
- Filed: 2011-02-03
- Published: 2011-05-26
- Granted: 2013-10-29
- Earliest claimed: 2006-09-29
- Assignees: GM Global Technology Operations LLC
- Applicants: David A. Arthur; Abdullah B. Alp
- Inventors: David A. Arthur; Abdullah B. Alp
- Web page: https://patentgrep.com/patent/US8568935B2

## CPC

- H01M 8/04992: characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
- H01M 8/04089: of gaseous reactants
- H01M 8/04395: {of cathode reactants at the inlet or inside the fuel cell}
- H01M 8/0491: {of fuel cell stacks}
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A method for managing fuel cell power increases in a fuel cell system using an air flow feedback delay. The method comprises the steps of determining a required air mass flow rate at a predetermined point in the fuel cell system, determining an actual air mass flow at a predetermined point in the fuel cell system, calculating an air flow feedback delay as a function of the required air mass flow rate and the actual air mass flow, and delaying an external circuit from increasing current draw from the fuel cell stack by the magnitude of the air flow feedback delay.

## Claims

### Claim 1

A method for managing fuel cell power increases in a fuel cell system using air flow feedback delay, the method comprising the steps of:
a. determining gas flow effecting characteristics of an air flow path of the fuel cell system between a compressor supplying air and a cathode outlet of a fuel cell stack;
b. determining a required air mass flow rate at the cathode outlet to provide a predetermined current output from the fuel cell stack;
c. determining an actual air mass flow at a predetermined point in the air flow path;
d. calculating an air flow feedback delay as a function of the actual air mass flow and the gas flow effecting characteristics, wherein the gas flow effecting characteristics include a gas temperature, a gas pressure, and a static volume of a cathode of the fuel cell stack; and
e. delaying an external circuit from increasing current draw from the fuel cell stack by the magnitude of the air flow feedback delay.

### Claim 2 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of static volume, distance, internal roughness and laminar and/or turbulent flow effects of a line connected between the compressor and a cathode inlet of the fuel cell stack.

### Claim 3 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of static volume, distance, internal roughness and laminar and/or turbulent flow effects of a plurality of channels connected between the cathode outlet and a cathode inlet of the fuel cell stack.

### Claim 4 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of internal roughness and laminar and/or turbulent flow effects of an air mass flow sensor connected in the air flow path.

### Claim 5 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of internal roughness and laminar and/or turbulent flow effects of a back pressure valve connected in the air flow path.

### Claim 6 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of internal roughness and laminar and/or turbulent flow effects of a gas pressure sensor connected in the air flow path.

### Claim 7 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of internal roughness and laminar and/or turbulent flow effects of a temperature sensor connected in the air flow path.

### Claim 8 (depends on 1)

The method according to claim 1 including performing said step a. by determining at least one of internal roughness and laminar and/or turbulent flow effects of a humidifier connected in the air flow path.

### Claim 9 (depends on 1)

The method according to claim 1 including performing said step c. with an air mass flow sensor connected in the air flow path at the predetermined point.