Analytical feedback design via interpolation approach for the strong stabilization of a magnetic bearing system

In this paper, a stable controller has been designed via an interpolation approach to stabilize an open-loop unstable MBC500 magnetic bearing system. An 8th-order model of the MBC500 magnetic bearing system was identified from the collected frequency response data. Since there are resonant modes that can threaten the stability of the closed-loop system, notch filters are employed to help to secure stability. The controller has been designed on the basis of a reduced 2nd-order unstable model. The performance of the controller has been tested via simulation and compared with that of a conventional lead compensator. The controller designed via the interpolation approach has also been coded in C and implemented in real time on a Digital Signal Processor (DSP) card. Both simulation and implementation results show that the controller designed via the interpolation approach is superior in both closed-loop step responses and disturbance rejection.