Patent ID: 9647282
Date: 2017-05-09
CPC Classifications: H01M,Y02E,Y02T

Claim:
1. A method of controlling a fuel cell system, wherein the fuel COD system comprises: a fuel cell which generates power by supplying a fuel gas to an anode and supplying an oxidant gas to a cathode; a fuel gas supply path through which the fuel gas supplied to the anode flows; a fuel off-gas exhaust path through which a fuel off-gas exhausted from the anode flows; an oxidant gas supply path through which the oxidant gas supplied to the cathode flows; an oxidant off-gas exhaust path through which an oxidant off-gas exhausted from the cathode flows; an oxidant off-gas circulation path which connects the oxidant gas supply path and the oxidant off-gas exhaust path; an oxidant gas supply unit which supplies the oxidant gas to the cathode; an oxidant off-gas circulation unit which is arranged on the oxidant off-gas circulation path and circulates the oxidant off-gas; a fuel off-gas circulation path which connects the fuel gas supply path and the fuel off-gas exhaust path; and a fuel off-gas circulation unit which is arranged on the fuel off-gas circulation path and circulates the fuel off-gas, wherein the method of controlling the fuel cell system comprises: a stop command sensing process of sensing a stop command output when the fuel cell system stops; an anode pressure increasing process of increasing pressure so that pressure of the anode reaches a first predetermined pressure value after the stop command has been sensed in the stop command sensing process; and a stop-time discharge process of performing discharge by consuming oxygen remaining within the oxidant off-gas while driving the oxidant off-gas circulation unit after the anode pressure increasing process, wherein in the stop-time discharge process, the discharge continues while adjustment is performed so that the pressure of the anode is set to a second predetermined pressure value less than the first predetermined pressure value and a current value of the discharge is determined in correspondence with the real number of rotations of the fuel off-gas circulation unit, and wherein the stop-time discharge process is performed by driving the fuel off-gas circulation unit.