Abstract: In a converter for a switched reluctance motor, a dump capacitor receives freewheeling current from each phase and resupplies the charge to the dc supply. In this manner, residual magnetic energy is recovered and phase current quickly reduced while the converter requires only one main switching device and one freewheeling device per phase and the converter allows a unipolar source to be used.

Abstract: A method and apparatus for operating a switched reluctance motor at high efficiency, without requiring a shaft position sensor, allows dynamic increase of the torque margin as the dwell angle of the phase currents is changed in response to a change in load torque. Average current supplied by the DC link is sensed as a measure of load torque and is used to control the dwell angle.

Abstract: A permanent magnet rotor has a north and a south pole piece each separated into two sections by a central nonmagnetic insert to reduce the quadrature flux. The pole piece sections are welded to the central nonmagnetic insert, two nonmagnetic segments are welded to either end of the north pole piece and two magnetic segments are welded to either end of the south pole pieces to form two half rings. The half rings are secured about a solid shaft of magnetic material having a central portion with a rhombic cross section. The centerline of the half rings is aligned with the diagonal of the square central portion. The half rings are bolted to one another. The sides of the shaft and the inner faces of the half rings form four apertures extending the axial length of the pole pieces. A magnet which adds no structural strength to the rotor is positioned in each of the apertures, respectively.

Abstract: A rotor for a permanent magnet machine comprises laminated pole pieces held in position by interpolar nonmagnetic clamp pieces bolted to a solid rotor core having central portions with a polygonal cross section. Magnets are situated between the pole pieces and the faces of the central portion of the rotor and held in place by the clamping of the pole pieces. Pole piece bars are situated in axial extending apertures circumferentially arranged at the periphery of the pole pieces. Clamp piece bars are situated in channels in the clamp pieces. End rings electrically and structurally connect the clamp piece bars and pole piece bars at either axial end of the rotor forming a uniformly distributed starting cage.

Abstract: Plural stage commutation for a switched reluctance drive is performed by a converter circuit which short-circuits half of a bifilar phase winding, or an entire phase winding, for a controlled period in the second commutation stage so as to increase output power of the drive without increasing peak current in the switching device of the converter.

Abstract: A permanent magnet rotor has a north and a south pole piece each separated into two sections by a central nonmagnetic insert to reduce the quadrature flux. The pole piece sections are welded to the central nonmagnetic insert, two nonmagnetic segments are welded to either end of the north pole piece and two magnetic segments are welded to either end of the south pole pieces to form two half rings. The half rings are secured about a solid shaft of magnetic material having a central portion with a rhombic cross section. The centerline of the half rings is aligned with the diagonal of the square central portion. The half rings are bolted to one another. The sides of the shaft and the inner faces of the half rings form four apertures extending the axial length of the pole pieces. A magnet which adds no structural strength to the rotor is positioned in each of the apertures, respectively.

Abstract: A permanent magnet rotor uses a magnetic shaft having a rhomboidal cross section. Fastening means secure clamp pieces which in turn retain pole pieces and the permanent magnets.

Abstract: A two-pole rotor of increased flux concentration factor employs two pole pieces of magnetic material which are separated from each other by non-magnetic segments. The pole pieces and non-magnetic segments are joined together to form a cylinder with an aperture extending axially through the central portion. Two magnets forming a V shaped configuration and polarized such that the inner faces of the magnets have like polarity are positioned in the central portion of the cylinder with the outer sides of the magnets adjacent to one of the pole pieces. The magnets are located symmetrically about the d axis and asymmetrically about the q axis. The magnets extend above and below the q axis. A prism shaped segment of magnetic material is positioned between the magnets with the base of the prism adjacent to the other pole piece to hold the magnet in place. A stub shaft is mounted on each face of the cylinder.