Performance and Dynamic Properties of an Active Axial Bearing

In magnetically levitated systems at least one degree of freedom has to be actively stabilized. This is usually achieved with a linear magnetic actuator. If not prevented by e.g. lamination, eddy currents take place in the field conducting iron. These eddy currents have a strong effect on the field distribution in the iron and further reduce the force per current at higher frequencies. In this paper investigate the dynamic properties of a non laminated actuator biased with a permanent magnet in the rotor is anlaysed. It is shown that the voltage to force transfer function is practically unaffected by eddy currents.