Fuel cell power supply

• US 20020172847A1
• Filed: 04/05/2002
• Published: 11/21/2002
• Est. Priority Date: 04/05/2001
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Saeki, Hibiki, Aoyagi, Satoshi, Watanabe, Kazunori, Kotaka, Kazuo
• Granted Patent: US 7,005,204 B2
• Time in Patent Office: Days
• US Class Current: 429/24
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04567 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04597 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04895 Current
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• 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 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A fuel cell power supply has a fuel cell and a capacitor which are connected parallel to each other, and controls the amount of a reacting gas supplied to the fuel gas based on a target supply current. A capacitor open voltage calculator calculates an open voltage (Vcap_O) of the capacitor from a detected current (Icap) of the capacitor, an output voltage (Vout) of the fuel cell, and an internal resistance (Rcap) of the capacitor. A corrective quantity calculator calculates a corrective quantity (Ifc AM) for a target supply current (Ifc_REQ) based on the open voltage (Vcap O) of the capacitor, the output voltage (Vout) of the fuel cell, and the target supply current (Ifc_REQ), so as to prevent an air compressor from operating excessively and also prevent the fuel cell from suffering a gas shortage, depending on current-voltage characteristic data (Icap−Vcap) of the fuel cell and current-voltage characteristic data (Ifc−Vcap) of the capacitor.

Claims

1. A fuel cell power supply comprising:

a fuel cell;

reacting gas supply means for supplying a reacting gas to said fuel cell;

fuel cell control means for controlling an amount of the reacting gas supplied from said reacting gas supply means to said fuel cell based on a target supply current determined depending on a current demanded by a load when said fuel cell is connected to the load and a current is supplied to the load;

a capacitor connected parallel to said fuel cell and chargeable by said fuel cell, said capacitor being dischargeable to supply the current demanded by the load when said target supply current increases within a time shorter than a response delay which is caused in said fuel cell while said fuel cell control means controls an output current of said fuel cell, and the output current of said fuel cell is smaller than the current demanded by the load;

charging/discharging state recognizing means for recognizing a charging/discharging state of said capacitor; and

target supply current correcting means for, when said target supply current undergoes a change causing said response delay, performing at least one of a first correcting process of reducing said target supply current if said change is an increase in said target supply current, and a second correcting process of increasing said target supply current if said change is a reduction in said target supply current, depending on the charging/discharging state of said capacitor recognized by said charging/discharging state recognizing means.

2. A fuel cell power supply according to claim 1, wherein said charging/discharging state recognizing means comprises means for recognizing an open voltage of said capacitor as said charging/discharging state, and said target supply current correcting means comprises means for performing said first correcting process by determining a prescribed voltage at which a current produced by adding a discharging current of said capacitor depending on said prescribed voltage which is recognized from voltage-current characteristic data of said capacitor based on the open voltage of said capacitor recognized by said charging/discharging state recognizing means, to the output current of said fuel cell depending on the prescribed voltage which is recognized from voltage-current characteristic data of said fuel cell, is equal to said target supply current, and subtracting the discharging current of said capacitor depending on said prescribed voltage from said target supply current.

3. A fuel cell power supply according to claim 1, wherein said charging/discharging state recognizing means comprises means for recognizing an open voltage of said capacitor as said charging/discharging state, and said target supply current correcting means comprises means for performing said second correcting process by determining a prescribed voltage at which a current produced by subtracting a charging current of said capacitor depending on said prescribed voltage which is recognized from voltage-current characteristic data of said capacitor based on the open voltage of said capacitor recognized by said charging/discharging state recognizing means, from the output current of said fuel cell depending on the prescribed voltage which is recognized from voltage-current characteristic data of said fuel cell, is equal to said target supply current, and adding the charging current of said capacitor depending on said prescribed voltage to said target supply current.

4. A fuel cell power supply according to claim 2 or 3, further comprising:

capacitor voltage detecting means for detecting an output voltage of said capacitor;

memory means for storing resistance data of an internal resistance of said capacitor; and

capacitor current detecting means for detecting a charging/discharging current of said capacitor;

said charging/discharging state recognizing means comprising means for calculating a voltage drop across said internal resistance based on the resistance data stored by said memory means and the charging/discharging current detected by said capacitor current detecting means, and recognizing the open voltage of said capacitor from the voltage detected by said capacitor voltage detecting means and said calculated voltage drop.