Patent ID: 8248018

Claim:
A motor controller that controls a permanent magnet motor including a rotor including a plurality of low coercivity permanent magnets having a coercivity low enough to allow modification in amount of magnetization, the motor controller comprising: a position detector including one or more position sensors to detect a rotational position of the rotor; an inverter circuit that is connected between a direct current voltage supply source and windings of the permanent magnet motor and that is configured by a plurality of semiconductor switching elements of multiple phases connected thereto; and a magnetization controller that magnetizes the plurality of low coercivity permanent magnets by energizing the windings through the inverter circuit, wherein all of the low coercivity permanent magnets are magnetized to a uniform level of magnetization by energizing the windings twice at a same electric angle belonging to different electric angle periods specified based on a sensor signal outputted by the position sensor.