Fuel cell power supply device

• US 20030008188A1
• Filed: 06/28/2002
• Published: 01/09/2003
• Est. Priority Date: 06/28/2001
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Asano, Yutaka, Saeki, Hibiki, Aoyagi, Satoshi
• Granted Patent: US 7,060,380 B2
• Time in Patent Office: Days
• US Class Current: 429/23
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/34 by heating
• CPC Class Codes: H01M 8/04328 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04335 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04388 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04395 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04567 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• 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 8/0491 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 10/70 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

Disclosed is a fuel cell power supply device which can accurately determine a requested output current of a fuel cell depending on an electric energy requested by a load even if output current/voltage characteristics of the fuel cell change. A power supply management control unit 14 has an I-V characteristics estimating unit 52 for estimating output current/voltage characteristics (I-V characteristics) of a fuel cell by substituting a linear function (V=F(I)) in which a gradient indicates an internal resistance (Rfc) of the fuel cell and an interception of an axis representing a voltage (V) indicates an open-circuit voltage (Vfc_o) of the fuel cell calculated by a fuel cell open-circuit voltage calculator 51 for the I-V characteristics. On the basis of the I-V characteristics of the fuel cell estimated by the I-V characteristics estimating unit 52, a requested output voltage determining unit 53 and a requested output current determining unit 54 determine a requested output voltage (Vfc_REQ) and a requested output current (Ifc_REQ), respectively, which are needed to obtain a target total electric energy (Psys).

Claims

1. A fuel cell power supply device comprising:

a fuel cell;

reactive gas supply means for supplying supplies reactive gases to said fuel cell;

supplied-amount regulating means for regulating regulates an amount of reactive gases supplied from said reactive gas supply means to the fuel cell;

requested output current determining means for determining a requested output current of the fuel cell depending on a requested electric energy of a load when said load is connected to the fuel cell and is then supplied with an electric energy;

gas supply control means for permitting said supplied-amount regulating means to control the amount of reactive gases supplied to the fuel cell so as to obtain said requested output current;

first storage means for storing data of an internal resistance of the fuel cell;

fuel cell open-circuit voltage recognizing means for recognizing an open-circuit voltage of the fuel cell; and

output characteristics estimating means for estimating output current/voltage characteristics of the fuel cell by substituting a linear function in which a gradient indicates the internal resistance of the fuel cell and an intercept of an output voltage axis indicates the open-circuit voltage of the fuel cell for the output current/voltage characteristics,

wherein said requested output current determining means determines an output current of the fuel cell, which is obtained by applying the requested electric energy of the load to said linear function, as the requested output current.

2. The fuel cell power supply device according to claim 1, further comprising:

fuel cell current detecting means for detecting an output current of the fuel cell,

wherein when the output current of the fuel cell obtained by applying the requested electric energy of the load to the linear function is smaller than a current detected by said fuel cell current detecting means, the requested output current determining means determines the detected current as the requested output current.

3. The fuel cell power supply device according to claim 1, further comprising:

an electric double layer capacitor which is connected parallel to the fuel cell;

second storage means for storing data of an internal resistance of said electric double layer capacitor;

capacitor open-circuit voltage recognizing means for recognizing an open-circuit voltage of the electric double layer capacitor;

capacitor charged/discharged current recognizing means for dividing a difference between the requested output voltage, obtained by applying the requested output current to the linear function, and the open-circuit voltage of the electric double layer capacitor by the internal resistance of the electric double layer capacitor to recognize a current charged into or discharged from the electric double layer capacitor when an output voltage of the electric double layer capacitor is equivalent to the requested output voltage; and

requested output current correcting means for performing at least one of a first correction to subtract a discharged current from the requested output current when said capacitor charged/discharged current recognizing means recognizes the current discharged from the electric double layer capacitor and a second correction to add a charged current to the requested output current when the capacitor charged/discharged current recognizing means recognizes the current charged into the electric double layer capacitor.

4. The fuel cell power supply device according to claim 3, further comprising:

fuel cell current detecting means for detecting an output current of the fuel cell,

wherein when the requested output current subjected to said first correction or said second correction by said requested output current correcting means is smaller than a current detected by said fuel cell current detecting means, the requested output current determining means determines the detected current as the requested output current.

5. The fuel cell power supply device according to any one of claims 1 to 4, wherein

the fuel cell open-circuit voltage recognizing means recognizes the open-circuit voltage of the fuel cell every predetermined cycle and

the output characteristics estimating means estimates the output current/voltage characteristics of the fuel cell by substituting the linear function for the output current/voltage characteristics every said predetermined cycle.