Drive circuit for synchronous motor, synchronous motor driven by drive circuit, air blower including synchronous motor, air conditioner including air blower, and method of driving synchronous motor

摘要

A drive circuit for a synchronous motor including a rotor having ten magnetic poles formed by a permanent magnet, and a stator in which a winding is wound in a concentrated manner around nine teeth facing the rotor, the drive circuit including: an inverter including a plurality of switching elements in bridge connection; and a control unit that controls the inverter in such a manner that a square-wave-shaped current flows to the winding, wherein the control unit operates in such a manner that an energization phase at which to pass the square-wave-shaped current falls within a range of electric angles of −10° to +5° from an energization phase at which the current is minimum when a target torque of the synchronous motor is generated.