Analysis of rotor shell losses in a magnetically levitated homopolar hollow-shaft permanent magnet synchronous motor

This paper analyzes challenges that arise when the rotational speed in magnetically levitated hollow-shaft PMSMs is increased. Going to higher speeds highlights the advantages of such machines as being contact and contamination free, but leads to considerably higher losses. We propose a model and supply experimental data and simulations to subdivide losses into different categories with regard to specific optimizations. We particularly focus on the high rotor shell eddy current losses specific for this machine.