- Volume 37 Issue 7
DOI QR Code
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.)
- 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
- Chiba, A., Fukao, T., Ichikawa, O., Ohima, M., Takemoto, M. and Dorrell, D.G., 2005, Magnetic Bearings and Bearingless Drives, Newnes, Oxford, U.K.
- Kim, D., 2001, "Control of a 3-Phase VR Type Self-Bearing Step Motor," Trans. Korean Soc. Mech. Eng. A, Vol. 25, No. 12, pp. 1974-1980.
- Kim, S. and Baek, Y., 2009, "Design and Analysis of Bearingless Generator Using Self-Sensing Magnetic Bearings," 2009 Fall Conference of KSME, pp. 1024-1029.
- Langley, L. W. and Fisher, R. L., 1985, "Toroidally Wound Brushless DC Motor," US Patent 4,547,713.
- Lee, H. I. and Noh, M., 2011, "Optimal Design of Radial-Flux Toroidally-Wound Brushless DC Machines," IEEE Trans. Ind. Electr., Vol. 58, No. 2, pp. 444-449. https://doi.org/10.1109/TIE.2010.2054052
- Lee, H. I., Yoo, S.Y. and Noh, M., 2010, "Toroidally-Wound Self-Bearing BLDC Motor with Lorentz Force," IEEE Trans. Magn., Vol. 46, No. 6, pp. 2148-2151. https://doi.org/10.1109/TMAG.2010.2043065