Patent ID: 7771883

Claim:
A fuel cell system comprising: a fuel cell module including a cathode input responsive to a charge airflow and a cathode exhaust; a compressor generating the airflow applied to the cathode input of the fuel cell module; a mass flow meter responsive to the airflow sent to the compressor, and generating a signal indicative of the speed of the airflow through the compressor; a motor for driving the compressor; and a controller responsive to the signal from the mass flow meter, said controller providing a signal to the motor to control the speed of the compressor, said controller storing a compressor map of the compressor, said controller determining the discharge pressure and temperature of the compressor from the speed of the compressor and the airflow signal from the mass flow meter, said controller further determining the location on the compressor map at which the system is operating and preventing the compressor from entering a surge condition.