• DocumentCode
    1623320
  • Title

    Drag loss in retaining rings of permanent magnet motors

  • Author

    Kirtley, James L., Jr. ; Lovelace, Edward C.

  • Volume
    2
  • fYear
    2003
  • Firstpage
    1068
  • Abstract
    Slot openings modulate the magnetic field present in the air-gap of permanent magnet motors. If the magnets are conductive or if there is present a conductive magnet retention cylinder, losses will be present. This is no-load loss which appears as a drag on the rotor. It is difficult to distinguish from core loss, at least from terminal measurements, but in some cases can cause severe rotor heating. In this paper we present a simple method for estimating this drag loss, which is easily mitigated by proper selection of air-gap dimensions and slot openings.
  • Keywords
    air gaps; eddy currents; losses; parameter estimation; permanent magnet motors; rotors; air-gap; air-gap dimensions; conductive magnet retention cylinder; core loss; drag loss; eddy current model; field disturbance; losses; magnetic field; no-load loss; permanent magnet motors; retaining rings; rotor; rotor heating; slot openings; terminal measurements; Air gaps; Core loss; Engine cylinders; Heating; Loss measurement; Magnetic fields; Magnetic losses; Magnetic modulators; Permanent magnet motors; Rotors;
  • fLanguage
    English
  • Publisher
    ieee
  • Conference_Titel
    Electric Machines and Drives Conference, 2003. IEMDC'03. IEEE International
  • Print_ISBN
    0-7803-7817-2
  • Type

    conf

  • DOI
    10.1109/IEMDC.2003.1210367
  • Filename
    1210367