Fractional order sliding mode controller for a solid-core magnetic bearing system

This paper proposes a novel type of fast convergence robust controller for a non-laminated magnetic bearing system whose dynamics is governed by a non-commensurate fractional order model. The key feature of this approach is the use of Fractional Order PID sliding manifolds and the appropriate sliding mode control law developed to assure the robustness. The stability of the closed loop system is ensured by the fractional-order stability theorems. Under the stable performance of system, the parameters of sliding mode surface are tuned by the given crossover frequency and the phase margin. Finally, simulations are carried out to indicate the effectiveness of the proposed robust fractional-order controller.