Comparative Evaluation of Polyphase Bearingless Slice Motors for Fluid-Handling Applications

For the bearingless slice motor (BSM) concept, which has been successfully introduced in semiconductor fluid-handling and medical applications over the last years, different motor configurations in terms of stator construction, number of phases, and winding arrangement exist. This paper comparatively evaluates these topologies for their suitability in possible future industry applications, such as the food, biotechnology, and pharmaceutical industries. The comparison is carried out for two-, three-, and four-phase BSM concepts based on performance indexes such as motor losses, losses in the power electronics, and voltampere requirements depending on the required magnetic bearing force and the motor torque. Finally, the performance data are discussed, and also, practical aspects such as realization effort, copper and iron mass, control effort, and scalability of the concepts are taken into account.