A Self-Healing Magnetic Bearing

A fault tolerantmagneticbeatingcontrolscheme,whichindependentlycontrolseachstatorpoleusinga proportional-integral-derivativ(ePID) displacemenfteedback,hasbeenanalyticallytested. The scheme was applied to a 16-pole magnetic beating with a load capacity of 6000 lb and a static load of 4000 lb. Transient response simulation of pole failures (such as those caused by power amplifier failure or coil short circuit) demonstrated that the rotor recovered its bearing center position in a fraction of a second after two consecutive failures of the two top load-carrying poles. The scheme does not require on-line current monitoring to determine the pole failure patterns or storage of precalculated control data to counteract pole failures.