Method of determining voltage condition of fuel cell vehicle

• US 20060012340A1
• Filed: 06/01/2005
• Published: 01/19/2006
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Saeki, Hibiki, Aoyagi, Satoshi
• Granted Patent: US 7,436,148 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/04888 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A method of determining voltage conditions of a fuel cell vehicle which includes a motor as a driving force source of the vehicle, a motor control device for controlling operation of the motor, a fuel cell, to which a reaction gas is supplied, for generating electric power by an electrochemical reaction, and a battery device which is charged by the electric power generated by the fuel cell and sends and receives electrical energy to and from the motor by control of the motor control device. The method includes setting a voltage value, typically an average value, of an output voltage of the fuel cell within a range from a minimum value to a maximum value of an open circuit voltage of the battery device. Even when the fuel cell and the battery device are directly connected, overcharge or overdischarge can be prevented, thereby reducing frequency of voltage conversion.

Claims

1. A method of determining voltage conditions of a fuel cell vehicle, wherein:

the fuel cell vehicle includes a motor as a driving force source of the vehicle, a motor control device for controlling operation of the motor, a fuel cell, to which a reaction gas is supplied, for generating electric power by an electrochemical reaction, and a battery device which is charged by the electric power generated by the fuel cell and sends and receives electrical energy to and from the motor by control of the motor control device; and

the method includes setting a voltage value of an output voltage of the fuel cell within a range from a minimum value to a maximum value of an open circuit voltage of the battery device.

2. The method as claimed in claim 1, wherein:

the fuel cell vehicle further includes a voltage conversion device for increasing or decreasing a terminal voltage of the battery device and outputting the converted voltage; and

the method includes setting an average of the output voltage of the fuel cell within a range from the minimum value to the maximum value of the open circuit voltage of the battery device.

4. The method as claimed in claim 1, wherein the method includes setting a maximum value of a terminal voltage of the battery device to be greater than a sum of an average of an open circuit voltage of the battery device and a terminal voltage of the battery device which corresponds to a maximum value of a charging current for charging the battery device.

5. The method as claimed in claim 2, wherein the method includes setting a maximum value of a terminal voltage of the battery device to be greater than a sum of an average of an open circuit voltage of the battery device and a terminal voltage of the battery device which corresponds to a maximum value of a charging current for charging the battery device.

7. The method as claimed in claim 4, wherein the terminal voltage of the battery device which corresponds to the maximum value of the charging current is a product of the maximum value of the charging current and an internal resistance of the battery device.

8. The method as claimed in claim 1, wherein the output voltage of the fuel cell is set in accordance with an output characteristic of the fuel cell and a predetermined running state of the fuel cell vehicle.

9. The method as claimed in claim 8, wherein the predetermined running state is set to a running state which most frequently appears.

3. A method of determining voltage conditions of a fuel cell vehicle, wherein:

the fuel cell vehicle includes a motor as a driving force source of the vehicle, a motor control device for controlling operation of the motor, a fuel cell, to which a reaction gas is supplied, for generating electric power by an electrochemical reaction, and a battery device which is charged by the electric power generated by the fuel cell and sends and receives electrical energy to and from the motor via the motor control device; and

the method includes setting a maximum value of a terminal voltage of the battery device to be greater than a sum of an average of an open circuit voltage of the battery device and a terminal voltage of the battery device which corresponds to a maximum value of a charging current for charging the battery device.

6. The method as claimed in claim 3, wherein the terminal voltage of the battery device which corresponds to the maximum value of the charging current is a product of the maximum value of the charging current and an internal resistance of the battery device.