Fuel cell system and fuel supply method thereof

A fuel cell system comprising:

• a fuel treating unit to modify fuel to produce hydrogen;
• a stack to generate energy through an electrochemical reaction of the hydrogen with oxygen;
• a fuel supplying unit to supply the fuel to the fuel treating unit;
• and
• a main controller to control the fuel supplying unit, wherein the fuel supplying unit supplies a supply amount of reformer fuel required in real time for a reformer to perform the modification, and a supply amount of burner fuel required in real time for a burner to heat the reformer.

A fuel supply method of a fuel cell system to generate energy through an electrochemical reaction of hydrogen produced through modification of fuel with oxygen, comprising:

• determining a supply amount of reformer fuel supplied to a reformer to perform the modification;
• determining a supply amount of burner fuel supplied to a burner to heat the reformer;
• determining a fuel supply amount of a fuel pump based on the determined reformer fuel supply amount and the determined burner fuel supply amount, and controlling an operation of the fuel pump based on the determined fuel supply amount of the fuel pump;
• and
• controlling a flow rate of fuel supplied to the reformer and a flow rate of fuel supplied to the burner, wherein the flow rates supply, in real time, the determined reformer and burner fuel supply amounts.