Method of controlling purge of fuel cell system for vehicle

Patent metadata

Field	Value
Publication number	US-10811709-B2
Application number	US-201615277135-A
Country	US
Kind code	B2
Filing date	Sep 27, 2016
Priority date	Dec 17, 2015
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A method of controlling purge of a fuel cell system for a vehicle is provided. The method determines whether a purge function is normally performed in controlling purge of discharging nitrogen, hydrogen, and vapor within an anode of a fuel cell system. Particularly, the method confirms whether purge is performed by measuring a duty or a current applied to a hydrogen supply valve and measuring a change in the duty before and after an application of a purge valve operation command while adjusting a pressure inside the anode, which supplies hydrogen, to be uniform. Further, a hydrogen supply amount supplied into an anode is estimated and a change rate of a hydrogen supply amount supplied to the anode and a hydrogen amount consumed during a generation of the fuel cell system are estimated during a purge function, to determine whether purge is actually performed based on the estimated information.

First claim

What is claimed is:

1. A method of controlling purge of a fuel cell system for a vehicle,
comprising:
applying, by a controller, a purge valve driving signal for opening or closing a purge valve, and detecting valve duties of a hydrogen supply valve before and after the application of the purge valve driving signal;
calculating, by the controller, a difference value between the valve duty of the hydrogen supply valve after the application of the purge valve driving signal and the valve duty of the hydrogen supply valve before the application of the purge valve driving signal, and comparing the difference value with a predetermined threshold value; and
determining, by the controller, whether the purge valve is operated without error by comparing the calculated difference value with the threshold value,
wherein the valve duty of the hydrogen supply valve corresponds to a consumed current of the hydrogen supply valve, and a consumed current of the hydrogen supply valve is measured instead of the valve duty of the hydrogen supply valve, and whether the purge valve is opened is determined using the measured consumed current value.

2. The method of claim 1 , wherein when the calculated difference value is equal to or greater than the threshold value, the purge valve is determined to opened or closed without error.

3. The method of claim 1 , wherein when the calculated difference value is less than the threshold value, the purge valve is determined to open or close with an error, and the controller is configured to transmit an opening or closing signal of the purge valve again.

4. The method of claim 3 , further comprising:
entering, by the controller, an emergency stage to prevent hydrogen from leaking in response to determining that the purge valve is closed with the error.

5. A method of controlling purge of a fuel cell system for a vehicle,
comprising:
applying, by a controller, a purge valve opening signal, and detecting valve duties of a hydrogen supply valve before and after the application of the purge valve driving signal;
calculating, by the controller, a difference value between the valve duty of the hydrogen supply valve after the application of the purge valve opening signal and the valve duty of the hydrogen supply valve before the application of the purge valve opening signal, and comparing the difference value with a first predetermined threshold value; and
when the calculated difference value calculated is equal to or greater than the first threshold value, determining, by the controller, that the purge valve is opened;
applying, by the controller, a purge valve closing signal, and detecting the valve duty of the hydrogen supply valve after the application of the purge valve closing signal;
calculating, by the controller, a difference value between the valve duty of the hydrogen supply valve after the application of the purge valve closing signal and the valve duty of the hydrogen supply valve after the application of the purge valve opening signal, and comparing the difference value with a second predetermined threshold value; and
when the calculated difference value calculated is equal to or greater than the second threshold value, determining, by the controller, that the purge valve is closed,
wherein the valve duty of the hydrogen supply valve corresponds to a consumed current of the hydrogen supply valve, and a consumed current of the hydrogen supply valve is measured instead of the valve duty of the hydrogen supply valve, and whether the purge valve is opened and closed is determined using the measured consumed current value.

6. The method of claim 5 , wherein when the calculated difference value calculated is less than the first threshold value, the purge valve is determined to be closed, and the controller is configured to transmit a purge valve opening signal again.

7. The method of claim 5 , wherein when the calculated difference value calculated is less than the second threshold value, the purge valve is determined to be opened.

8. The method of claim 7 , further comprising:
entering, by the controller, an emergency stage to prevent hydrogen from leaking in response to determining that the purge valve is opened.

9. A method of controlling purge of a fuel cell system for a vehicle, comprising:
applying, by a controller, a purge valve driving signal for opening or closing a purge valve, and calculating a difference between a hydrogen supply amount to a stack and a hydrogen consumption amount by the stack for before and after the application of the purge valve driving signal;
calculating, by the controller, a characteristic value (d1=|c2−c1|) based on a second difference value (c2) between the hydrogen supply amount and the hydrogen consumption amount after the application of the purge valve driving signal and a first difference value between the hydrogen supply amount and the hydrogen consumption amount before the application of the purge valve driving signal, and comparing the characteristic value with a predetermined threshold value; and
determining, by the controller, whether the purge valve is operated without error by comparing the calculated characteristic value calculated with the threshold value,
wherein the hydrogen supply amount is determined based on mapping data of a consumed current and the hydrogen supply amount of the hydrogen supply valve, and the hydrogen consumption amount is determined based on a current amount output from the stack.

10. The method of claim 9 , wherein when the calculated characteristic value is equal to or greater than the threshold value, the purge valve is determined to be opened or closed without error.

11. The method of claim 9 , wherein when the calculated characteristic value is less than the threshold value, the purge valve is determined to be opened or closed with an error, and the controller is configured to transmit an opening or closing signal of the purge valve again.

12. The method of claim 11 , further comprising:
entering, by the controller, an emergency stage to prevent hydrogen from leaking in response to determining that the purge valve is closed with the error.

13. A method of controlling purge of a fuel cell system for a vehicle, comprising:
applying, by a controller, a purge valve opening signal, and calculating a difference between a hydrogen supply amount to a stack and a hydrogen consumption amount by the stack for before and after the application of the purge valve opening signal;
calculating, by the controller, a first characteristic value (d1=|c2−c1|) based on a sec difference value (c2) between the hydrogen supply amount and the hydrogen consumption amount after the application of the purge valve opening signal and a first value (c1) between the hydrogen supply amount and the hydrogen consumption amount before the application of the purge valve opening signal, and comparing the first characteristic value with a first predetermined threshold value;
when the first calculated characteristic value is equal to or greater than the first threshold value, determining, by the controller, that the purge valve is opened;
applying, by the controller, a purge valve closing signal, and calculating a difference between a hydrogen supply amount and a hydrogen consumption amount after the application of the purge valve closing signal;
calculating, by the controller, a second characteristic value (d2=|c4−c3|) based on a fourth difference value (c4) between the hydrogen supply amount and the hydrogen consumption amount after the application of the purge valve closing signal and a third difference value (c3) between the hydrogen supply amount and the hydrogen consumption am

Assignees

• Hyundai Motor Co Ltd

Inventors

• Jung Se Kwon
• Kwon Bu Kil

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/04589

  of fuel cell stacks · CPC title

• H01M8/04656

  of auxiliary devices, e.g. batteries, capacitors · CPC title

• Y02T90/40

  Application of hydrogen technology to transportation, e.g. using fuel cells · CPC title

• H01M2250/20

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