Motor driving device, circuitry for controlling motor driving device, control method of motor driving device, and air conditioner

An air conditioner comprising:

• a plurality of permanent magnet synchronous motors;
• and
• a motor driving device to drive at least one permanent magnet synchronous motor among the plurality of permanent magnet synchronous motors, wherein
• the motor driving device includes:
• an inverter to supply an alternating current;
• a switch to change a number of the at least one permanent magnet synchronous motor to which the alternating current is supplied from the inverter;
• a detector to detect a detection value corresponding to the alternating current supplied to the at least one permanent magnet synchronous motor;
• and
• circuitry to control the inverter and the switch-unit, wherein
• the circuitry sets an overcurrent interruption threshold value at a value based on the number, and
• when the detection value is greater than or equal to the overcurrent interruption threshold value, the circuitry makes the inverter stop the supplying of the alternating current to the at least one permanent magnet synchronous motor.

A control method of a motor driving device for controlling the motor driving device, the motor driving device comprising an inverter to supply an alternating current to at least one permanent magnet synchronous motor, a switch to change a number of the at least one permanent magnet synchronous motor to which the alternating current is supplied from the inverter;

• and a detector to detect a detection value corresponding to the alternating current supplied to the at least one permanent magnet synchronous motor, wherein
• the control method comprising:
• setting an overcurrent interruption threshold value at a value based on the number, and
• when the detection value is greater than or equal to the overcurrent interruption threshold value, making the inverter stop the supplying of the alternating current to the at least one permanent magnet synchronous motor.