Frequency response of an actuator with solid iron core

This paper is concerned with a new method for a derivation of frequency response of an actuator with solid iron core. This actuator is designed for a magnet bearing of thrust-direction at a high-speed motor. The rotor of this motor is levitated by magnetic bearings. Authors developed a high-speed permanent magnet synchronous motor and other components of this system including the magnet bearings and this controller. To design the control system of the actuator, we want transfer function of plant described by polynomial expression because this makes design of controller easy.