Fuel cell power supply
First Claim
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, andmeans 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.
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Accused Products
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.
28 Citations
6 Claims
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1. A fuel cell power supply comprising:
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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. - View Dependent Claims (2, 3, 4)
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5. A fuel cell power supply comprising:
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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 of the fuel cell when said fuel cell is connected to a 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 a current demanded by the load when the current demanded by the load increases within a time shorter than a response delay of said fuel cell and the output current of said fuel cell becomes short; charging/discharging state recognizing means for recognizing a charging/discharging state of said capacitor; target supply current determining means for determining said target supply current depending on said current demanded by the load and the charging/discharging state of said capacitor recognized by said charging/discharging state recognizing means immediately after the current demanded by the load increases within a time shorter than a response delay of said fuel cell and the output current of said fuel cell becomes short, 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 determining means comprises means for 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 current demanded by the load, and subtracting the discharging current of said capacitor depending on said prescribed voltage from said current demanded by the load, 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. - View Dependent Claims (6)
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Specification