MOTOR DRIVE DEVICE, AND FAN CONTROL DEVICE AND HEAT PUMP DEVICE UTILIZING SAME

摘要

Provided is a motor drive device that is capable of activating a motor without causing such an abnormality as the application of an overvoltage or an overcurrent to an inverter when reactivating the motor from a state in which the motor is still rotating after deactivation due to inertia. When stopping a fan motor (51) that drives an indoor fan (15), a microcomputer (30) of the motor drive device (20) stops an inverter (25) after having the number of revolutions of the fan motor (51) reduced to a predetermined number of revolutions. The fan motor (51) is a brushless DC motor that is driven by means of sensorless rotor position control once the fan motor is activated. Because the inverter (25) is stopped after the number of revolutions of the fan motor (51) is reduced to the predetermined number of revolutions, the number of revolutions of the motor at the time of the reactivation is equal to or lower than the predetermined number of revolutions.