Performance Comparison of Wire-wound and PCB Windings for Passively Levitated Self-Bearing Machines

Fully passively levitated self-bearing machines have recently been introduced to increase compactness and reliability of magnetically suspended systems while lowering their cost. An electromechanical model allowing to predict their force and torque capabilities as well as the resulting rotor dynamics has been established and experimentally validated. However, although these machines rely on a combined armature winding, the potential design trade-off between the motor and suspension performance has not been investigated yet. Besides, despite the specific characteristics of the machine under study, no analysis of the optimal winding configuration has been carried out so far. In this context, this paper first proposes motor and suspension performance metrics also applicable to conventional self-bearing motors. On this basis, classic wire-wound concentrated and overlapping windings are objectively compared through an optimisation process to printed circuit board (PCB) windings, the latter enabling more elaborate coil shapes offering higher flux linkages along with lower resistances.