Control method and system of fuel cell system

Patent metadata

Field	Value
Publication number	US-10062916-B2
Application number	US-201514737676-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Dec 9, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A control method and system of a fuel cell system is provided. The control method includes detecting, by a controller, a voltage of a fuel cell stack when power generation of a fuel cell is stopped while a fuel cell vehicle is being driven. In addition, hydrogen supply pressure at an anode side is adjusted based on a variation in the detected voltage.

First claim

What is claimed is:

1. A control method of a fuel cell system, comprising:
detecting, by a controller, a voltage of a fuel cell stack when stopping power generation of a fuel cell while a fuel cell vehicle is driven; and
adjusting, by the controller, a hydrogen supply pressure at an anode side based on the detected voltage, further comprising: shutting off, by the controller, a supply of air to the fuel cell stack before adjusting the hydrogen supply pressure,
wherein adjusting the hydrogen supply pressure at the anode side includes:
reducing, by the controller, the hydrogen supply pressure as the detected voltage of the fuel cell stack is decreased, and

wherein an amount of cross-over hydrogen from the anode side to the cathode side is minimized when stopping power generation of the fuel cell.

2. The control method of claim 1 , wherein adjusting the hydrogen supply pressure is performed when the voltage of the fuel cell stack is less than a predetermined reference voltage after stopping the power generation of the fuel cell.

3. The control method of claim 2 , wherein the predetermined reference voltage is a voltage of when the voltage of the fuel cell stack has been reduced by a load after stopping the power generation of the fuel cell.

4. The control method of claim 1 , wherein adjusting the hydrogen supply pressure further includes:
adjusting a voltage of a main bus terminal connected at an output side of the fuel cell stack to be greater than the voltage of the fuel cell stack.

5. The control method of claim 1 , wherein adjusting the hydrogen supply pressure at the anode side includes:
increasing, by the controller, the hydrogen supply pressure when the voltage of the fuel cell stack is increased due to inflow of air to the fuel cell stack.

6. The control method of claim 1 , wherein adjusting the hydrogen supply pressure at the anode side adjusts the hydrogen supply pressure with a hysteresis range based the variation in the voltage of the fuel cell stack.

7. The control method of claim 1 , further comprising:
comparing, by the controller, a preset reference time period with a processing time for adjusting the hydrogen supply pressure at the anode side; and
further purging, by the controller, the anode with hydrogen when restarting power generation of the fuel cell, when the processing time is greater than the preset reference time period based on the reduced hydrogen supply pressure.

8. The control method of claim 7 , wherein the number of times that further purging is performed is proportional to the processing time exceeding the preset reference time period.

9. The control method of claim 1 , further comprising:
comparing, by the controller, a preset reference pressure with a time integral of the difference between hydrogen supply pressure reduced by adjusting the hydrogen supply pressure and an initial hydrogen supply pressure in which power generation of the fuel cell is stopped; and
further purging, by the controller, the anode with hydrogen when restarting power generation of the fuel cell, when the integral is greater than the preset reference pressure.

10. The control method of claim 9 , wherein the number of times that further purging is performed is proportional to the difference between the time integral and the preset reference pressure.

11. The control method of claim 1 , further comprising:
comparing, by the controller, a preset amount of nitrogen with a time integral of a transfer rate of nitrogen moved into an anode side by adjusting the hydrogen supply pressure; and
further purging, by the controller, the anode with hydrogen when restarting power generation of the fuel cell, when the integral value is greater than the preset amount of nitrogen.

12. The control method of claim 11 , wherein the number of times that further purging is performed is proportional to the difference between the integral and the preset amount of nitrogen.

13. The control method of claim 7 , further comprising:
supplying, by the controller, air to a cathode after an amount of hydrogen at the anode side reaches a target amount as the hydrogen supply pressure is increased by restarting the power generation of the fuel cell,
wherein further purging the anode with hydrogen is performed after supplying the air to the cathode.

14. The control method of claim 13 , wherein before the amount of hydrogen at the anode side reaches the target amount of hydrogen, a voltage of a main bus terminal connected at an output side of the fuel cell stack is adjusted to greater higher than the voltage of the fuel cell stack.

15. The control method of claim 1 , further comprising
comparing, by the controller, a preset reference time period with a processing time for adjusting the hydrogen supply pressure at the anode side; and
increasing, by the controller, hydrogen supply pressure during a predetermined time period when restarting power generation of the fuel cell when the processing time is greater than the preset reference time period based on the reduced hydrogen supply pressure.

16. The control method of claim 15 , wherein the processing time exceeding the preset reference time period is proportional to at least one of both the predetermined time period and the increased hydrogen supply pressure.

17. The control method of claim 1 , further comprising:
comparing, by the controller, a preset reference pressure with a time integral of the difference between hydrogen supply pressure reduced by adjusting the hydrogen supply pressure and an initial hydrogen supply pressure in which the power generation of the fuel cell is stopped; and
increasing, by the controller, hydrogen supply pressure during a predetermined time period when restarting the power generation of the fuel cell when the integral is greater than the preset reference pressure.

18. The control method of claim 17 , wherein the difference between the integral and the preset reference pressure is proportional to at least one of the predetermined time period and the increased hydrogen supply pressure.

19. The control method of claim 1 , further comprising:
comparing, by the controller, a preset amount of nitrogen with a time integral of a transfer rate of nitrogen moved into the anode side by adjusting the hydrogen supply pressure; and
increasing, by the controller, the hydrogen supply pressure during a predetermined time period when restarting power generation of the fuel cell when the integral is greater than the preset amount of nitrogen.

20. The control method of claim 19 , wherein the difference between the time integral and the preset amount of nitrogen is proportional to at least one of both the predetermined time period and the increased hydrogen supply pressure.

21. The control method of claim 11 , wherein the transfer rate of nitrogen is dependent on at least one among the group selected from: a humidified state of the fuel cell stack, a voltage of the fuel cell stack, and the difference between hydrogen supply pressure reduced by adjusting the hydrogen supply pressure and an initial hydrogen supply pressure in which the power generation of the fuel cell is stopped.

22. The control method of claim 11 , wherein the transfer rate of nitrogen is increased as a humidified state of the fuel cell stack increases, as a temperature of the fuel cell stack increases, as a voltage of the fuel cell stack decreases, and as the difference between hydrogen supply pressure reduced by adjusting the hydrogen supply pressure and

Assignees

• Hyundai Motor Co Ltd

Inventors

• Kwon Sang Uk
• Lee Heon Joong
• Jeon Yei Sik
• Yoon Sung Gone
• Son Ik Jae

Classifications

• H01M8/04231

  Purging of the reactants · CPC title

• H01M8/04888

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

• H01M8/04228

  during shut-down · CPC title

• H01M8/04225

  during start-up · CPC title

• H01M8/04303

  applied during shut-down · CPC title