초록 ▼

A control method for monitoring a fuel cell stack in a fuel cell system in which the actual voltage and actual current from the fuel cell stack are monitored. A preestablished relationship between voltage and current over the operating range of the fuel cell is established. A variance value between

A control method for monitoring a fuel cell stack in a fuel cell system in which the actual voltage and actual current from the fuel cell stack are monitored. A preestablished relationship between voltage and current over the operating range of the fuel cell is established. A variance value between the actual measured voltage and the expected voltage magnitude for a given actual measured current is calculated and compared with a predetermined allowable variance. An output is generated if the calculated variance value exceeds the predetermined variance. The predetermined voltage-current for the fuel cell is symbolized as a polarization curve at given operating conditions of the fuel cell.

대표청구항 ▼

1. A method for operating a fuel cell system with a fuel cell stack that supplies electrical power to an external load, comprising: monitoring actual stack operating voltage that is produced by said fuel cell stack; monitoring actual stack operating current that is produced by said fuel cell sta

1. A method for operating a fuel cell system with a fuel cell stack that supplies electrical power to an external load, comprising: monitoring actual stack operating voltage that is produced by said fuel cell stack; monitoring actual stack operating current that is produced by said fuel cell stack; looking up an expected stack voltage and a high voltage variation limit in a lookup table using said actual operating current of said fuel cell stack as a first lookup table reference; dividing said actual voltage by said expected voltage to generate an actual voltage variation signal; comparing said actual voltage variation signal to said high voltage variation limit; and generating a first signal if said actual voltage variation signal exceeds said high voltage variation limit. 2. The method of claim 1 further comprising: looking up a low voltage variation limit in said lookup table; comparing said actual voltage variation signal to said low voltage variation limit; and generating a second signal if said actual voltage variation signal exceeds said low voltage variation limit. 3. The method of claim 2 further comprising employing fuel cell stack temperature as a second lookup table reference. 4. The method of claim 2 further comprising employing fuel cell stack pressure as a second lookup table reference.