Control of a 3-Phase VR Type Self-Bearing Step Motor

3상 가변형 셀프 베어링 스텝모터의 제어

Kim, Dae-Gon

  • Published : 2001.12.01


The control algorithm of a new type self-bearing step motor is presented. The motor actuator is used for both motor and bearing functionality without any redundant coil windings or redundant electromagnets. The self$.$bearing step motor layout and its control method are described. A linearized farce-current-displacement relationship is derived. As the result of the unbalance response approach, the constant torque production is possible fur the supply current regulation algorithm. And even if the bearing functionality is added in the motor functionality, no additional current for bearing functionality is possible, and this leads to minimize the net power loss. Also, the unbalance response shows the independent bearing force and motor torque.


Self-Bearing Motor;Bearingless Motor;Magnetic Bearing;Step Motor;Self-Bearing Step Motor


  1. Takashi Kenjo, 1984, 'Stepping Motors and Their Microprocessor Controls,' Oxford University Press, Oxford
  2. Okada, Y., Miyamoto, S., and Ohishi. T., 1996, 'Levitation and Torque Control of Internal Permanent Magnet Type Bearingless Motor,' IEEE Transactions of Control System Technology, Vol. 4, No. 5, pp. 565-571
  3. Stephens, L. S. and Kim Daegon, 1999, 'A Segmented Arc Self-Bearing Motor,' United States Patent Office-Technical Application, pending
  4. Stephens, L.S. and Kim, D.G., 2000, 'Analysis and Simulation of a Lorentz-type, Slotless Self-Bearing Motor,' Proc. of the 1st IFAC Conference on Mechatronics, pp. 463-468
  5. Steele, B.A. and Stephens, L.S., 2000, 'A Test Rig for Measuring Force and Torque Production in A Lorentz, Slotless Self Bearing Motor,' Proc. 7th Int. Symposium on Magnetic Bearings, pp. 407-412
  6. Bischel, J., 1991, 'The Bearingless Electrical Machine,' Proc. International Symposium Magnetic Suspension Technology 91, NASA Publication 3152, pp. 561-573
  7. Chiba, A., Rahman, M.A., and Fukao.T., 1991, 'Radial Forces in Bearingless Reluctance Motor,' IEEE Transactions on Magnetics, Vol. 27, pp. 786-790
  8. Higuchi, 1987, 'Magnetically Floating Actuator Having Angular Positioning Function,' US Patent, NO.4683391
  9. Kim Daegon and Kim Kyungwoong, 1996, 'The Influence of Assembling Errors on the Performance of the Rotor Supported by Active Magnetic Bearings,' Journal of KSME, Vol. 20, No. 12, pp. 3909-3916
  10. Kim Daegon and Kim Kyungwoong, 1998, 'The Influence of the Maching and Assembling Errors on the Performance of the Shaft Supported by Active Magnetic Bearings,' JSME International Journal Series C, Vol. 41, No. 2, pp. 313-320