Patent ID: 6815104
Filing Date: 2004-11-09
Classification: H01M,Y02E

Abstract:
A method for controlling the flow rate of an oxidizer in a fuel cell system having a fuel cell stack performing power generation by being supplied with fuel and the oxidizer, a compressor for supplying the oxidizer to the fuel cell stack, a back pressure valve for controlling pressure of the oxidizer which is disposed in a flow passage of the oxidizer and downstream of the fuel cell stack, and a control device for controlling the fuel cell stack, the compressor, and the back pressure valve, the method comprising the steps of:calculating an oxidizer pressure command and an oxidizer flow rate command based on a given electrical current command using the control device; comparing a first flow rate that is defined as an upper limit of oxidizer flow rate corresponding to the oxidizer pressure command and a second flow rate that is defined as a lower limit of oxidizer flow rate corresponding to the oxidizer pressure command with the oxidizer flow rate command; and regulating the oxidizer flow rate command so as to be limited within a range from the second flow rate to the first flow rate.