Air-conditioner system for vehicle and method for controlling same

A method for controlling an air-conditioner system for a vehicle, which comprises:

• a variable capacity compressor;
• a condenser for condensing refrigerant discharged from the compressor;
• an electronic expansion valve which expands the refrigerant discharged from the condenser and is controlled in the degree of opening by a control signal of a controller;
• and an evaporator for evaporating the refrigerant discharged at the electronic expansion valve, and, which is controlled to a target superheat degree by a control of the degree of opening of the electronic expansion valve, the method comprising:
• a first step (S1) of deciding whether an amount of refrigerant discharged from the compressor is below a first set value (A) or not;
• and
• a second step (S2) of controlling the electronic expansion valve based on a first target superheat degree which is lower than the target superheat degree if the amount of refrigerant discharged from the compressor is below the first set value (A) as a result of the decision of the first step (S1).