Air-conditioning apparatus

An air-conditioning apparatus comprising:

• an indoor unit;
• and
• an outdoor unit including a compressor to compress a refrigerant and a motor drive system to drive the compressor,
• the motor drive system including
• an inverter to convert a DC voltage into an AC voltage,
• an electric motor including three stator windings with both ends open, to operate based on the AC voltage obtained by the inverter, and
• a connection state switching circuitry having a function
• to change a connection state of the three stator windings included in the electric motor, to set the connection state to a star connection at a start of operation of the electric motor in any of a cooling mode, a heating mode, and a defrost mode, and
• to select the connection state at a startup of the electric motor, based in part or in whole on:
• information related to an installation space of the indoor unit, a temperature and a humidity of the installation space, and a temperature difference between the temperature of the installation space and a set temperature,
• information related to distribution of the temperature and the humidity of the installation space and an operating condition of the air-conditioning apparatus,
• information related to temporal changes in the temperature and the humidity, and
• information related to temporal changes in the distribution of the temperature and the humidity,
• wherein, when the air-conditioning apparatus is operating, the connection state switching circuitry switches the connection state between the star connection and a delta connection without stopping operation of the compressor, based on the information related to the temperature difference between the temperature of the installation space and the set temperature.