METHOD OF CONTROLLING OPENING DEGREE OF AIR FLOW RATE CONTROL VALVE IN FUEL CELL STACK AND APPARATUS

An apparatus of a fuel cell system may perform a method comprising, based on entry into an idle operation state of a fuel cell stack of the fuel cell system after start-up of the fuel cell system, controlling airflow to the fuel cell stack such that a current of the fuel cell stack converges to a predetermined current, based on the current of the fuel cell stack converging to the predetermined current, controlling a voltage drop slope of a fuel-cell direct current DC-DC converter (FDC), and controlling, based on the controlled voltage drop slope of the FDC, an operation of the fuel cell stack.