Bearing Current Modelling and Investigation in Axial Flux Permanent Magnet Synchronous Motors for Aerospace Applications

This paper investigates the bearing current issue of the Axial Flux Permanent Magnet Synchronous Motors (AFPMSM) used in aerospace. The case-study examined in this work is an eVTOL propulsion motor. The paper focuses on calculating the various parasitic components that relate to the bearing current phenomena in the AFPMSM. The simulation work presented in this paper provides a good understanding of the bearing current phenomenon and the sensitivity of the different parameters on the bearing current. According to the authors' best knowledge, this is the first time investigating the bearing current problem in AFPMSM. The paper also proposes a model for the bearing current simulation in this machine. Once the importance of the problem had been assessed, the bearing current possibility and the different solutions to overcome this problem have been investigated. The study also shows the pros and cons of each of these suggested solutions from the electrical point of view.