Patent ID: 7485383
Filing Date: 2009-02-03
Classification: B60L,H01M,Y02E,Y02T

Abstract:
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; target supply current correcting means for, immediately after 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; 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, 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, and 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.