Electric power generation control system and electric power generation control method for fuel cell

• US 20060141305A1
• Filed: 03/23/2004
• Published: 06/29/2006
• Est. Priority Date: 04/10/2003
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kazama, Isamu
• Granted Patent: US 7,564,211 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• 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 2240/12 Speed
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 3/0053 relating to fuel cells
• CPC Class Codes: B60L 3/06 Limiting the traction current under mechanical overload conditions
• CPC Class Codes: B60L 50/72 Constructional details of fuel cells specially adapted for electric vehicles
• CPC Class Codes: B60L 58/32 for controlling the temperature of fuel cells, e.g. by controlling the electric load
• 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 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04231 Purging of the reactants
• CPC Class Codes: H01M 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04373 : of auxiliary devices, e.g. reformers, compressors, burners
• CPC Class Codes: H01M 8/04552 : of the individual fuel cell
• CPC Class Codes: H01M 8/0494 : of fuel cell stacks
• CPC Class Codes: H01M 8/04947 : of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 2300/30 : The power source being a fuel cell
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• 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 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A power generation control system for a fuel cell, which includes a rechargeable battery (5), and a controller (10) including: a unit (101) for computing a target power to be generated by a fuel cell (3); a unit (106) for detecting available power of the rechargeable battery (5); a unit (103) for limiting electric power to be extracted from the fuel cell (3) based on the detected power-lowering request and available power, and a unit (105) for controlling power extraction from the fuel cell (3) based on the computed target power and an output of the unit (103) for limiting electric power to be extracted. When a power-lowering request is detected, electric power to be extracted from the fuel cell (3) is reduced by an amount less than the available power of the rechargeable battery (5).

Claims

1. A power generation control system for a fuel cell, comprising:

a chargeable/dischargeable unit connected to a fuel cell, for being charged with electric power from the fuel cell and discharging electric power to a load;

a target power computing unit for computing a target power to be generated by the fuel cell;

a power-lowering request detection unit for detecting a power-lowering request to the fuel cell;

an available power detection unit for detecting available power of the chargeable/dischargeable unit;

a power extraction limiting unit for limiting electric power to be extracted from the fuel cell based on the power-lowering request detected by the power-lowering request detection unit and the available power detected by the available power detection unit; and

a power extraction control unit for controlling electric power to be extracted from the fuel cell based on the target power computed by the target power computing unit and an output of the power extraction limiting unit,

wherein, as the power-lowering request detection unit detects a power-lowering request, the power extraction limiting unit reduces electric power to be extracted from the fuel cell by an amount less than the available power of the chargeable/dischargeable unit.

2. The power generation control system for a fuel cell according to claim 1, wherein,

as the power-lowering request detection unit detects another power-lowering request, the power extraction limiting unit further reduces electric power to be extracted from the fuel cell.

3. The power generation control system for a fuel cell according to claim 1, wherein

the power-lowering request detection unit comprises a cell voltage detection unit for detecting a cell voltage of the fuel cell, wherein the power-lowering request is provided based on the cell voltage detected by the cell voltage detection unit.

4. The power generation control system for the fuel cell according to claim 3, wherein

the power extraction limiting unit keeps the electric power to be extracted from the fuel cell reduced until the cell voltage detected by the cell voltage detection unit is recovered to a predetermined voltage.

5. The power generation control system for the fuel cell according to claim 1, wherein

the power-lowering request detection unit comprises a temperature detection unit for detecting a cell temperature of the fuel cell, wherein the power-lowering request is provided based on the cell temperature detected by the temperature detection unit.

6. The power generation control system for the fuel cell according to claim 5, wherein

the power extraction limiting unit keeps the electric power to be extracted from the fuel cell reduced until the cell temperature detected by the temperature detection unit drops below a predetermined temperature.

7. The power generation control system for the fuel cell according to claim 1, wherein

the power-lowering request detection unit comprises:

a purge gas combustor; and

a combustor temperature detection unit for detecting a temperature of the purge gas combustor, wherein

the power-lowering request is provided based on the temperature detected by the combustor temperature detection unit.

8. The power generation control system for the fuel cell according to claim 7, wherein

the power extraction limiting unit keeps the electric power to be extracted from the fuel cell reduced until the temperature detected by the combustor temperature detection unit drops below a predetermined temperature.

9. The power generation control system for the fuel cell according to claim 2, wherein

the power extraction limiting unit increases the amount of reduction in electric power to be extracted from the fuel cell to the available power of the chargeable/dischargeable unit by a predetermined amount while the power-lowering request detection unit detects a power-lowering request, and

the power extraction limiting unit decreases the amount of reduction in electric power to be extracted from the fuel cell by another predetermined amount while the power-lowering request detection unit detects no power-lowering request.

10. A method of controlling electric power to be generated by a fuel cell, the method comprising:

providing a chargeable/dischargeable unit for being charged with electric power from the fuel cell and discharging electric power to a load;

computing target power to be generated by the fuel cell;

detecting power-lowering request to the fuel cell;

detecting available power of the chargeable/dischargeable unit;

limiting electric power to be extracted from the fuel cell based on the detected power-lowering request and the detected available power; and

controlling the electric power to be extracted from the fuel cell based on the computed target power and the limited electric power to be extracted;

wherein, as the power-lowering request is detected, the electric power to be extracted from the fuel cell is reduced by an amount less than the available power of the chargeable/dischargeable unit.