Air-conditioning apparatus with defrost bypass circuit

An air-conditioning apparatus comprising:

• a refrigerant circuit including
• a main circuit in which a compressor, a cooling/heating switching device, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger including a plurality of parallel outdoor heat exchangers are connected by refrigerant pipes, and
• a bypass circuit connected, by a pipe, to each of the plurality of parallel outdoor heat exchangers via a defrosting refrigerant pressure-reducing device, a defrosting flow passage switching device, and a backflow prevention device, the defrosting refrigerant pressure-reducing device being configured to reduce a pressure of refrigerant that branches off from the main circuit, by adjusting a flow rate of the refrigerant in a refrigerant pipe that branches off from a discharge pipe at the compressor, the defrosting flow passage switching device being configured to switch a flow passage for refrigerant that is supplied to one of the plurality of parallel outdoor heat exchangers, the backflow prevention device being provided between the defrosting flow passage switching device and the cooling/heating switching device to prevent backflow of refrigerant to a suction side of the compressor, the bypass circuit being configured to cause part of refrigerant discharged from the compressor to branch off from the discharged refrigerant;
• and
• a controller configured to individually control operations of the compressor, the pressure reducing device, the defrosting refrigerant pressure-reducing device, and the defrosting flow passage switching device,
• wherein the controller switches the flow passage for use in introduction of refrigerant using the defrosting flow passage switching device, to select one of the plurality of parallel outdoor heat exchangers as a defrosting target to be defrosted and supplies defrosting refrigerant whose pressure is reduced by the defrosting refrigerant pressure-reducing device to the selected one of the plurality of parallel outdoor heat exchangers.