Patent ID: 7151335

Claim:
A permanent magnet rotating electric machine comprising a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which polarity is alternately arranged in a peripheral direction in a rotor iron core, wherein: said iron core of said permanent magnet rotor is composed of: magnetic pole pieces positioned on an air gap face of an outer periphery of said permanent magnets for forming a magnetic path of said permanent magnets, auxiliary magnetic poles extending toward said air gap face of said permanent magnets for producing reluctant torque, and a rotor yoke positioned said permanent magnets for forming a magnetic path of said auxiliary salient poles and said permanent magnets, and further includes: concavities formed on said air gap face of said magnetic pole pieces of said rotor iron core of said permanent magnets, inclined from a central part of said magnetic poles to each end thereof, wherein, in a high speed region where induced voltage of the permanent magnets is higher than a terminal voltage of the motor, the stator winding current is controlled by weak field control so as to be applied to the permanent magnets as demagnetizing force, and said concavities reduce a high frequency component of the iron loss during the weak field control.