Stop control method for fuel cell system

Patent metadata

Field	Value
Publication number	US-2019288308-A1
Application number	US-201816017103-A
Country	US
Kind code	A1
Filing date	Jun 25, 2018
Priority date	Mar 14, 2018
Publication date	Sep 19, 2019
Grant date	—

Abstract

A stop control method for a fuel cell system of a vehicle can include: determining whether a fuel cell of the fuel cell system is shut down when a key-off signal is received; comparing a voltage of the fuel cell with a first set voltage when it is determined that the fuel cell is not shut down; controlling a voltage of a high-voltage terminal downwardly when the voltage of the fuel cell is larger than the first set voltage; turning on a cathode oxygen depletion (COD) relay a first time after controlling the voltage of the high-voltage terminal downwardly; turning off a high-voltage terminal relay a first time after turning on the COD relay, the high-voltage relay disposed between the fuel cell and the high-voltage terminal; and shutting down the fuel cell and performing key-off control after turning off the high-voltage terminal relay.

First claim

What is claimed is:

1 . A stop control method for a fuel cell system of a vehicle, the stop control method comprising:
determining, by a controller, whether a fuel cell of the fuel cell system is shut down when a key-off signal is received indicating that key-off of the vehicle is required; comparing, by the controller, a voltage of the fuel cell with a first set voltage when it is determined that the fuel cell is not shut down; controlling, by the controller, a voltage of a high-voltage terminal downwardly when the voltage of the fuel cell is larger than the first set voltage; turning on, by the controller, a cathode oxygen depletion (COD) relay a first time after controlling the voltage of the high-voltage terminal downwardly; turning off, by the controller, a high-voltage terminal relay a first time after turning on the COD relay, the high-voltage relay disposed between the fuel cell and the high-voltage terminal; and shutting down, by the controller, the fuel cell and performing key-off control after turning off the high-voltage terminal relay.

2 . The stop control method of claim 1 , wherein the turning off of the high-voltage terminal relay the first time comprises turning off, by the controller, the high-voltage terminal relay the first time when a difference between the voltage of the fuel cell and the voltage of the high-voltage terminal is less than a second set voltage.

3 . The stop control method of claim 1 , further comprising:
turning off, by the controller, the high-voltage terminal relay a second time when it is determined that the fuel cell is shut down; and turning on, by the controller, the COD relay a second time after turning off the high-voltage terminal relay the second time, wherein the shutting down of the fuel cell is performed after turning on the COD relay the second time.

4 . The stop control method of claim 3 , wherein the turning off of the high-voltage terminal relay the second time comprises turning off, by the controller, the high-voltage terminal relay the second time when the voltage of the fuel cell is equal to or less than the first set voltage.

5 . The stop control method of claim 1 , wherein the shutting down of the fuel cell comprises shutting down, by the controller, the fuel cell when the voltage of the fuel cell is equal to or less than a third set voltage which is lower than the first set voltage.

6 . A stop control system comprising:
a fuel cell system of a vehicle, the fuel cell system including a fuel cell; and a controller equipped in the vehicle, the controller configured to:
determine whether the fuel cell is shut down when a key-off signal is received indicating that key-off of the vehicle is required,
compare a voltage of the fuel cell with a first set voltage when it is determined that the fuel cell is not shut down,
control a voltage of a high-voltage terminal downwardly when the voltage of the fuel cell is larger than the first set voltage,
turn on a cathode oxygen depletion (COD) relay a first time after controlling the voltage of the high-voltage terminal downwardly,
turn off a high-voltage terminal relay a first time after turning on the COD relay, the high-voltage relay disposed between the fuel cell and the high-voltage terminal, and
shut down the fuel cell and performing key-off control after turning off the high-voltage terminal relay.

7 . A non-transitory computer readable medium containing program instructions for performing a stop control method for a fuel cell system of a vehicle, the program instructions when executed by a controller causing the controller to:
determine whether a fuel cell of the fuel cell system is shut down when a key-off signal is received indicating that key-off of the vehicle is required; compare a voltage of the fuel cell with a first set voltage when it is determined that the fuel cell is not shut down; control a voltage of a high-voltage terminal downwardly when the voltage of the fuel cell is larger than the first set voltage; turn on a cathode oxygen depletion (COD) relay a first time after controlling the voltage of the high-voltage terminal downwardly; turn off a high-voltage terminal relay a first time after turning on the COD relay, the high-voltage relay disposed between the fuel cell and the high-voltage terminal; and shut down the fuel cell and performing key-off control after turning off the high-voltage terminal relay.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Park Gun Hyung
• Kim Hyun Hie

Classifications

• H01M8/04955

  Shut-off or shut-down of fuel cells · CPC title

• H01M8/0488

  of fuel cell stacks · CPC title

• H01M8/04925

  Power, energy, capacity or load · CPC title

• H01M8/04303 Primary

  applied during shut-down · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title