Patent ID: 8334667
Filing Date: 2012-12-18
Classification: H02K,H02P,Y10T

Abstract:
1. A permanent magnet motor drive system comprising: a permanent magnet motor employing permanent magnets; an inverter to drive the permanent magnet motor; and a magnetize means to pass a magnetizing current for controlling flux of the permanent magnets, wherein: the permanent magnet motor employs two or more kinds of permanent magnets having different shapes or different magnetic characteristics, to form a magnetic pole, a plurality of the magnetic poles forming a rotor; and the magnetize means passes for a short time a d-axis current through an armature coil of the permanent magnet motor, to generate a magnetic field to magnetize at least a permanent magnet of one kind at each magnetic pole and irreversibly change a flux amount of the permanent magnet and changes a current phase of an armature coil current, to pass a magnetizing current, and passes a d-axis current through the armature coil in a direction for strengthening a magnetic flux of the permanent magnet of which magnetic flux is irreversibly changed when torque is generated and when a torque command is equal to or higher than a predetermined value.