Nonlinear Control of Zero Power Magnetic Bearing Using Lyapunov's Direct Method

This paper proposes a new nonlinear control system to realize a zero power control based magnetic bearings. It is not necessary for the proposed scheme to use not only permanent magnet but also bias current. The behavior of a rotor is controlled by the nonlinear control scheme which is derived based on Lyapunov’s direct method. The control currents to the electromagnets which stand opposite to each other are switched like on and off respectively depending on a displacement, a velocity, a rotation and an angular velocity of the rotor. It is clarified through the simulation that the proposed nonlinear control scheme is a useful approach to realize a zero power control of the magnetic bearing system.