Adaptive controller for stabilisation of rotational motion of a vertical shaft magnetic bearing

摘要

This paper proposes an adaptive controller to stabilise the rotational motion of a vertical shaft magnetic bearing. The gyroscopic coupling between the vertical and horizontal motion depends on rotational angular velocity and for variable speed applications, this velocity is considered an unknown parameter. Moreover, there are uncertainties in the mechanical and electrical parameters of the magnetic bearing model. This motivates the application of adaptive control to magnetic bearing system. The proposed adaptive controller is a model reference controller which uses the air gap measurement only as a feedback signal. The adaptive control system is proven to be globally asymptotically stable using Lyapunov direct method. Simulation results show the effectiveness of the proposed method.