Method of controlling opening speed of purge valve according to purge gas concentration and active purge system thereof

An active purge system (APS), comprising:

• a fuel tank configured to accommodate fuel;
• a canister configured to receive fuel evaporative gas from the fuel tank;
• a gas discharge line that connects the canister to an intake manifold;
• a purge control solenoid valve (PCSV) configured to open and close the gas discharge line;
• and
• a purge controller configured to:
• based on executing a purge operation of the PCSV to open the PCSV, vary a valve opening speed of the PCSV based on any one among (i) a low concentration rate coefficient determined based on whether a gas concentration condition is satisfied, (ii) a high concentration rate coefficient determined based on whether an air-fuel ratio variability condition is satisfied, (iii) a coolant temperature rate coefficient determined based on an ambient air temperature and an engine coolant temperature that is less than a setting value, or (iv) an ambient air temperature rate coefficient determined based on an ambient air temperature condition and the engine coolant temperature that is greater than or equal to the setting value, and
• perform a purge control based on a difference in the valve opening speed.