Protective control system for magnetic suspension and magnetically suspended devices

摘要

A protective control system is provided in a magnetic suspension system having a permanent magnetic and an electro-magnetic circuit for levitating a spinning rotor; normally effective axial stability between limiting positions is provided by a feed back servo system supplying control currents to a pair of solenoids for modulating the permanent magnetic field in the suspension gaps. The physical support system and the suspended apparatus are protected from damage due to excessive axial oscillatory translation of the suspended rotor by detection of such non-linear events and by the removal of the suspension command for a suitable time period. The suspension control is then returned to its initial state and is again set into operation to translate the suspended element asymptotically and smoothly to its desired central location.