Control system for bearingless motor-generator

• US 7,456,537 B1
• Filed: 12/15/2005
• Issued: 11/25/2008
• Est. Priority Date: 12/17/2004
• Status: Expired due to Fees

• Current Assignee: University of Toledo
• Original Assignee: University of Toledo
• Inventors: Dever, Timothy P., Kascak, Peter E., Jansen, Ralph H.
• Primary Examiner(s): MULLINS, BURTON S
• Application Number:
  US11/304,359
• Time in Patent Office: 1,076 Days
• Field of Search: 310/90.5
• US Class Current: 310/90.5
• CPC Class Codes: F16C 32/0446 Determination of the actual position of the moving member, e.g. details of sensors
• CPC Class Codes: F16C 32/0493 integrated in an electrodynamic machine, e.g. self-bearing motor
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: H02P 21/0003 Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
• CPC Class Codes: H02P 25/16 characterised by the circuit arrangement or by the kind of wiring

Abstract

A control system for an electromagnetic rotary drive for bearingless motor-generators comprises a winding configuration comprising a plurality of individual pole pairs through which phase current flows, each phase current producing both a lateral force and a torque. A motor-generator comprises a stator, a rotor supported for movement relative to the stator, and a control system. The motor-generator comprises a winding configuration supported by the stator. The winding configuration comprises at least three pole pairs through which phase current flows resulting in three three-phase systems. Each phase system has a first rotor reference frame axis current that produces a levitating force with no average torque and a second rotor reference frame axis current that produces torque.

Claims

1. A control system for an electromagnetic rotary drive for use in the bearingless motor-generator having a permanent magnet, comprising:

a winding configuration having at least three pole pair systems through which phase currents flow resulting in three three-phase systems, each three-phase system having a first rotor reference frame current that produces a levitating force with no average torque and a second rotor reference frame current that produces torque, wherein the first rotor reference frame current produces flux that increases or decreases permanent magnet flux of the motor-generator and the second rotor reference frame current is in phase with back EMF of the motor-generator.

2. The control system of claim 1, wherein the first rotor reference frame current of the three pole pair systems produce six force vectors in six force directions.

3. A bearingless motor-generator having a permanent magnet, comprising:

a stator;

a rotor supported for movement relative to the stator; and

a control system having a winding configuration supported by the stator, the winding configuration comprising three or more pole pair systems through which phase currents flow resulting in three or more three-phase systems, each three-phase system having a first rotor reference frame current that produces a levitating force with no average torque and a second rotor reference frame current that produces torque,

wherein the first rotor reference frame current produces flux that increases or decreases permanent magnet flux of the motor-generator and the second rotor reference frame axis current is in phase with back EMF of the motor-generator.

4. The bearingless motor-generator of claim 3, wherein the first rotor reference frame axis currents of the three or more pole pair systems produce six or more force vectors in six or more force directions.