Method and system for diagnosing fuel cell stack

Patent metadata

Field	Value
Publication number	US-10052968-B2
Application number	US-201514616229-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Oct 6, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A system and method for diagnosing a fuel cell stack are provided. The method includes determining, by a controller, a time at which diagnosing the fuel cell stack is required based on a plurality of factors and driving a motor adjusted to a first efficiency value for a predetermined first reference time period based on the diagnosis determination. In addition, the controller is configured to drive the motor adjusted to a second efficiency value when the first reference time period has elapsed. A state of the fuel cell stack is then diagnosed based on a voltage variance of the fuel cell stack between driving the motor adjusted to the first efficiency value and second efficiency value.

First claim

What is claimed is:

1. A method for diagnosing a fuel cell stack, comprising:
determining, by a controller, a time at which diagnosing a fuel cell stack is required based on a plurality of factors;
driving, by the controller, a motor adjusted to a first efficiency value during a predetermined first reference time period from the time of diagnosis determination;
driving, by the controller, the motor adjusted to a second efficiency value after the first reference time period has elapsed;
diagnosing, by the controller, a state of a fuel cell stack based on a voltage variance of the fuel cell stack between driving the motor adjusted to the first efficiency value and second efficiency value; and
performing, by the controller, a dry-out recovery driving when the fuel cell stack is diagnosed as a dry-out state.

2. The method of claim 1 , further comprising:
determining, by the controller, whether a variance of an output current of the fuel cell stack is less than a predetermined variance.

3. The method of claim 1 , wherein the first efficiency value is less than the second efficiency value.

4. The method of claim 1 , wherein an output of the motor in the driving of the motor adjusted to the first efficiency value is the same as that in the driving of the motor adjusted to the second efficiency value.

5. The method of claim 1 , further comprising:
collecting, by the controller, data regarding a voltage variance by measuring a voltage variance during a predetermined second reference time period; and
diagnosing, by the controller, a state of the fuel cell stack by analyzing a resistance value based on the collected data.

6. The method of claim 1 , further comprising:
stopping, by the controller, an operation of a power conversion controller that adjusts charge and discharge of a high voltage battery between the high voltage battery and a fuel cell stack before the driving of the motor adjusted to the first efficiency value.

7. The method of claim 6 , further comprising:
resuming, by the controller, the operation of the power conversion controller when the diagnosis is terminated.

8. A method for diagnosing a fuel cell stack, comprising:
determining, by a controller, whether a variance of an output current of the fuel cell stack is less than a predetermined variance, whether diagnosing of the fuel cell stack is required, and whether a motor controller and a power conversion controller are in a normal state;
transmitting, by the controller, to the motor controller instructions for initiating a fuel cell stack diagnosis based on a result of the diagnosis determination, and stopping an operation of the power conversion controller, the instruction being for driving a motor adjusted to a first efficiency value during a predetermined first reference time period;
when the predetermined first reference time period has elapsed, transmitting, by the controller, to the motor controller instructions for terminating a fuel cell stack diagnosis to drive the motor adjusted to a second efficiency value, and resuming the operation of the power conversion controller;
diagnosing, by the controller, a state of the fuel cell stack based on a voltage variance of the fuel cell stack between when driving the motor adjusted to the first efficiency value and second efficiency value; and
performing, by the controller, a dry-out recovery driving when the fuel cell stack is diagnosed as a dry-out state.

9. A system for diagnosing a fuel cell stack, comprising:
a fuel cell controller configured to diagnose a state of the fuel cell stack by determining a time when diagnosing a fuel cell stack is required based on a plurality of factors, and perform a dry-out recovery driving when the fuel cell stack is diagnosed as a dry-out state; and
a motor controller configured to drive a motor adjusted to a first efficiency value for a predetermined first reference time period based on a result of the diagnosis determination, drive the motor adjusted to a second efficiency value when the first reference time period has elapsed, and transmit to the fuel cell controller a resistance value analyzed based on a voltage variance of the fuel cell stack between driving the motor adjusted to the first efficiency value and second efficiency value,
wherein the fuel cell controller is configured to diagnose a state of the fuel cell stack based on the transmitted resistance value.

10. The system of claim 9 , wherein the fuel cell controller is configured to determine whether a variance of an output current of the fuel cell stack is less than a predetermined variance.

11. The system of claim 10 , wherein the fuel cell controller is configured to operate the motor controller to drive the motor adjusted to a first efficiency value when diagnosing the fuel cell stack is required and the variance of an output current of the fuel cell stack is less than the predetermined variance.

12. The system of claim 9 , further comprising:
a power conversion controller configured to adjust charge and discharge of a high voltage battery between the high voltage battery and the fuel cell stack,
wherein the fuel cell controller is configured to determine whether the power conversion controller and the motor controller are in a normal state.

13. The system of claim 12 , wherein the fuel cell controller is configured to stop an operation of the power conversion controller and operate the motor controller to drive the motor adjusted to a first efficiency value in response to determining that the power conversion controller and the motor controller are in a normal state.

14. The system of claim 9 , wherein the first efficiency value is less than the second efficiency value.

15. The system of claim 9 , wherein an output of the motor when driving the motor adjusted to a first efficiency value is the same as that when driving the motor adjusted to a second efficiency value.

16. The system of claim 13 , wherein the fuel cell controller is configured to resume the operation of the power conversion controller when the diagnosis is complete.

17. A non-transitory computer readable medium containing program instructions executed by a controller, the computer readable medium comprising:
program instructions that determine a time at which diagnosing a fuel cell stack is required based on a plurality of factors;
program instructions that drive a motor adjusted to a first efficiency value during a predetermined first reference time period from the time of diagnosis determination;
program instructions that drive the motor adjusted to a second efficiency value after the first reference time period has elapsed;
program instructions that diagnose a state of a fuel cell stack based on a voltage variance of the fuel cell stack between driving the motor adjusted to the first efficiency value and second efficiency value; and
program instructions that perform a dry-out recovery driving when the fuel cell stack is diagnosed as a dry-out state.

18. The non-transitory computer readable medium of claim 17 , further comprising:
program instructions that determine whether a variance of an output current of the fuel cell stack is less than a predetermined variance.

19. The non-transitory computer readable medium of claim 17 , wherein the first efficiency value is less than the second efficiency value.

20. The non-transitory computer readable medium of claim 17 , wherein an output of the motor in the driving of the motor adjusted to the first efficiency value is the same as that in the driving of the moto

Assignees

• Hyundai Motor Co Ltd

Inventors

• Chung Sung Jin
• Koo Ja Hoo
• Lee Joon Yong
• Kwon Soon Woo

Classifications

• H01M8/04589

  of fuel cell stacks · CPC title

• B60L2240/547

  Voltage · CPC title

• H01M8/04649

  of fuel cell stacks · CPC title

• B60L2240/80

  Time limits · CPC title

• H01M8/04559 Primary

  of fuel cell stacks · CPC title