Patent ID: 7968241

Claim:
A fuel cell system comprising: a fuel cell that generates an electric power by a reaction of a reaction gas; a flow rate detector provided on a passage connecting a reaction gas source to the fuel cell, wherein the flow rate detector detects a flow rate of the reaction gas supplied to the fuel cell; a pressure detector provided on the passage connecting the reaction gas source to the fuel cell, wherein the pressure detector detects a pressure of the reaction gas supplied to the fuel cell; a flow rate control unit programmed to control the flow rate of the reaction gas; a pressure control unit programmed to control the pressure of the reaction gas; and a pressure control range calculating unit programmed to continuously calculate a controllable range of the pressure control unit on the basis of at least one of the detected flow rate and the detected pressure without using preset values when the fuel cell system operates in a normal status, an output transition status detection unit programmed to detect whether the fuel cell is in an output transition status, wherein: the flow rate control unit is programmed to control the flow rate on the basis of the calculated pressure controllable range, the flow rate detector and the pressure detector are coupled to the pressure control range calculating unit, the pressure control range calculating unit is programmed to continuously calculate the controllable range on the basis of the detected flow rates and the detected pressures without using preset values by calculating a range of maximum values when the pressure control unit is fully open and by calculating a range of minimum values when the pressure control unit is fully closed, the pressure control range calculating unit is further programmed to omit the detected flow rates and the detected pressures when the fuel cell is in the output transition status from calculating the controllable range, and the fuel cell is controlled using the calculated controllable range.