Identification and mixed-sensitivity H∞ control of permanent magnet biased axial magnetic bearing with multiple air gaps
- Resource Type
- Authors
- Kang Wang; Lei Tao Wu; Zhen Zhong Su; Dong Wang
- Source
- 2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD).
- Subject
- Engineering
Control theory
business.industry
law
Dynamic factor
Magnet
Eddy current
PID controller
Magnetic bearing
Sensitivity (control systems)
business
Finite element method
law.invention
- Language
Due to the solid cores, eddy currents have significant influence on the dynamic performance of permanent magnet biased axial magnetic bearing (MB) with multiple air gaps. In this paper, the dynamic current factor is identified as a 3rd-order transfer function while the dynamic displacement factor is identified as a 2nd-order transfer function based on the results obtained by the finite element method (FEM), and the model uncertainty is determined by the closed-loop system test. The method of designing mixed-sensitivity H∞ controller for the axial MB is analyzed. The designed H∞ controller is proved to be effective by the experimental results. It has higher steady-state accuracy and much better high-frequency noise attenuation capability than the PID controller.