Magnetically Self-Bearing Drive System for Ultracentrifugation: Toward 100 000 rpm and 200 000 g

A novel magnetically double self-bearing drive system for ultracentrifugation in pharmaceutical and chemical industry is presented, built as a prototype and operated. The prototype successfully reached its operating speed of
$100^{\prime }000\,\text{rpm}$
. It features an opening stator functionality allowing for fast removal of the ultracentrifuge rotor while enabling future centrifugal acceleration levels of
$200^{\prime }000\,\mathrm{g}$
. The openable stators require a stator encapsulation, provoking unavoidable stator yoke air-gaps. Parasitic induced phase-currents were identified, a current-control strategy proposed to diminish them and successfully implemented and operated on the prototype.