FUEL CELL OPERATING SYSTEM AND METHOD OF CONTROLLING OPERATION OF FUEL CELL

A fuel cell operating system including an air compressor disposed on an air supply line and configured to compress an oxidation gas to be supplied to a fuel cell stack and supply the compressed air to a fuel cell inlet side, an air discharge line configured to discharge the oxidation gas from the fuel cell stack, a bypass line configured to branch off from the air discharge line through a valve, connected to the air supply line, and configured to resupply the discharged oxidation gas to the fuel cell inlet side, and a control unit configured to control a flow rate of the oxidation gas to be supplied to the fuel cell stack by controlling the valve on the bypass line depending on a cell ratio value which is a ratio of the fuel cells each being applied with a voltage lower than a first voltage among the fuel cells.