Implementation of Levitation Controller for Toroidally-Wound Self-Bearing BLDC Motor Using Continuously Invertible Force Model

연속적 역변환이 가능한 힘 모델을 이용한 환형권선 셀프베어링 BLDC 모터의 부상 제어기 구현

  • Choi, Won-Yeong (Dept. of Mechatronics Engineering, Chungnam Nat'l Univ.) ;
  • Choi, Jung-Kyu (Dept. of Mechatronics Engineering, Chungnam Nat'l Univ.) ;
  • Noh, Myounggyu (Dept. of Mechatronics Engineering, Chungnam Nat'l Univ.)
  • 최원영 (충남대학교 메카트로닉스공학과) ;
  • 최정규 (충남대학교 메카트로닉스공학과) ;
  • 노명규 (충남대학교 메카트로닉스공학과)
  • Received : 2012.12.28
  • Accepted : 2013.04.17
  • Published : 2013.07.01


A self-bearing is an electric machine that achieves both rotational actuation and magnetic levitation using a single magnetic structure. To be able to stably levitate the rotor in a self-bearing, one needs to have an inverse of the force-current model. However, the force-current model in a self-bearing motor is typically not square. Furthermore, the elements of the matrix vary with respect to the rotational angle, resulting in singularities of the pseudo-inverse at various angles. In this paper, we propose a new force-current model that eliminates the singularities by adding a constraint in coil currents. This constraint eliminates the flux density in the stator core so that the saturation problem in the previous study is avoided. By implementing this force-current model, we are able to implement a levitation controller for a toroidally-wound self-bearing BLDC motor. The model inversion and levitation are validated experimentally.


Self-Bearing Motor;Magnetic Levitation;Force-Current Model


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