PURGE CONCENTRATION CALCULATION CONTROL METHOD IN ACTIVE PURGE SYSTEM AND FUEL AMOUNT CONTROL METHOD USING THE SAME

A purge concentration calculation control method in an active purge system for purging a fuel evaporation gas by using a purge pump may include: calculating the purge concentration by using the RPM of the purge pump, and the pressure at a rear end of the purge pump; and controlling a purge valve in order to satisfy a target purge flow rate and the purge fuel amount by using the calculated purge concentration.