Method of controlling operation mode of fuel cell in fuel cell vehicle

• US 9,168,845 B2
• Filed: 08/16/2013
• Issued: 10/27/2015
• Est. Priority Date: 05/07/2013
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Kwon, Sang Uk, Jeon, Soon Il
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Nelson, Sara
• Application Number:
  US13/968,863
• Publication Number:
  US 20140336855A1
• Time in Patent Office: 802 Days
• Field of Search: 701/22, 180/65.31, 429/9, 429/428
• US Class Current: 1/1
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2200/10 Air crafts
• CPC Class Codes: B60L 2200/18 Buses
• CPC Class Codes: B60L 2200/32 Waterborne vessels
• CPC Class Codes: B60L 2200/36 Vehicles designed to transport cargo, e.g. trucks
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 3/0053 relating to fuel cells
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/31 for starting of fuel cells
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60L 8/003 Converting light into electric energy, e.g. by using photo-voltaic systems
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

Disclosed is a method of controlling an operation mode of a fuel cell in a fuel cell vehicle wherein, (a) when a driver-demanded torque is lower than a first torque, and a current state of charge (SOC) in a battery is higher than a first SOC, the operation mode of the fuel cell is converted to a stop mode, and (b) when the driver-demanded torque is higher than a second torque, or the current SOC in the battery is lower than a second SOC, the operation mode is converted to a start mode, wherein the second torque is higher than the first torque and the second SOC is lower than the first SOC.

Claims

1. A method of controlling an operation mode of a fuel cell in a fuel cell vehicle, comprising:

determining by a controller a first torque and a first state of charge (SOC) corresponding to a stop mode torque value and a stop mode SOC value, and determining by a controller a second torque and a second SOC corresponding to a start mode torque value and a start more SOC value, wherein the second torque is higher than the first torque and the second SOC is lower than the first SOC;

when a driver-demanded torque is lower than the first torque, and a current SOC in a battery is higher than the first SOC, converting by the controller the operation mode of the fuel cell to a stop mode; and

when the driver-demanded torque is higher than the second torque, or the current SOC in the battery is lower than the second SOC, converting by the controller the operation mode of the fuel cell to a start mode,

wherein the first torque is increased to more quickly convert the operation mode to the stop mode or the second torque is reduced to more quickly convert the operation mode to the start mode according to driving state of the fuel cell vehicle.

2. The method according to claim 1, wherein during the stop mode and when the stop mode is not yet terminated, the stop mode is interrupted when the driver-demanded torque becomes higher than a third torque or the current SOC becomes lower than a third SOC, wherein the third torque is a predetermined torque ranging between the first and second torques, and the third SOC is a predetermined SOC ranging between the first and second SOCs.

3. The method of claim 1 wherein the first torque is increased to more quickly convert the operation mode to the stop mode.

4. The method of claim 1 wherein the second torque is reduced to more quickly convert the operation mode to the start mode according to driving state of the fuel cell vehicle.

5. The method according to claim 1, wherein as speed of the fuel cell vehicle is increased, the second torque is reduced to more quickly convert the operation mode to the start mode.

6. The method according to claim 1, wherein as available output voltage of the fuel cell is decreased, the second torque is reduced to more quickly convert the operation mode to the start mode.

7. The method according to claim 1, wherein the operation mode is converted to the start mode when the driver-demanded torque is higher than the second torque, when the current SOC is lower than the second SOC, or when a vehicle speed is equal to or higher than a predetermined speed and a voltage across both poles of the fuel cell is equal to or lower than a predetermined voltage.

8. The method according to claim 1, wherein during the start mode, the operation mode is not converted to the stop mode until the start mode has been maintained for at least a predetermined period of time.

9. A non-transitory computer readable medium containing program instructions executed by a controller, the computer readable medium comprising:

program instructions that determining a first torque, a first state of charge (SOC), a second torque and a second SOC of a fuel cell in a fuel cell vehicle;

program instructions that compare a driver-demanded torque to the first torque and that compare a current SOC to the first SOC;

program instructions that convert an operation mode of the fuel cell to a stop mode when the driver-demanded torque is lower than the first torque, and when the current SOC is higher than the first SOC;

program instructions that compare a driver-demanded torque to the second torque and a current SOC to the second SOC;

program instructions that convert the operation mode of the fuel cell to a start mode when the driver-demanded torque is higher than the second torque, and when the current SOC is lower than the second SOC; and

program instructions that determine when the fuel cell vehicle is in a regenerative braking state, a downhill driving state, an idle state, a rapid acceleration state, or a state of decrease in available output voltage;

program instructions that reduce the first SOC when the fuel cell is in the regenerative braking state;

program instructions that increase the first torque when the fuel cell is in the downhill driving state;

program instructions that increase the first torque when the fuel cell is in at least a portion of the idle state;

program instructions that reduce the second torque as speed of the fuel cell is increased; and

program instructions that reduce the second torque as available output voltage of the fuel cell is decreased.