Air-conditioning apparatus

An air-conditioning apparatus comprising:

• a coolant circuit configured by sequentially connecting a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger;
• a motor that operates a compressor mechanism disposed inside the compressor;
• an inverter for driving the motor;
• and
• a control unit that controls the inverter, wherein
• the control unit includes
• a liquefaction detecting unit that detects coolant liquefaction in the compressor;
• a first PWM signal generating unit that generates a carrier asynchronous pulse width modulation inverter control signal for driving the motor;
• a second PWM signal generating unit that generates a carrier synchronous pulse width modulation inverter control signal for making the motor perform a preheating operation;
• and
• a switch that performs switching in such a way that either one of the first PWM signal generating unit or the second PWM signal generating unit outputs a corresponding inverter control signal to the inverter.