Patent ID: 6057622
Filing Date: 2000-05-02
Classification: H02K,Y02T

Abstract:
A PM electrical machine, comprising:at least one stator forming a plurality of poles on opposite sides of a rotor operating space, at least two pairs of stator poles being formed, and a plurality of armature coils wound on said stator, wherein said armature coils operate with an armature voltage that is related to a flux in the stator;a rotor having an axis of rotation, said rotor being disposed in the rotor operating space and being separated by at least one portion of an air gap from said at least one stator, said rotor having no field windings and said rotor having a plurality of poles disposed around the axis of rotation, in which at least one of said poles contains permanent magnet material for producing air gap flux in said air gap, and another of said poles is without permanent magnet material, and wherein said rotor poles become aligned in operation with respective pairs of stator poles;a piece of ferromagnetic material assembled with said stator to provide a path for communicating a control flux to said stator and to said air gap through the plurality of stator poles and corresponding rotor poles; andat least one field weakening coil capable of receiving current from an external source, said field weakening coil being positioned to induce a field control flux in said piece of ferromagnetic material to adjust a magnitude and a polarity of the air gap flux through the plurality of rotor poles.