Design criteria and methodology of a Multi-Rim Carbon-fibre Flywheel to be integrated within a Large-Airgap PMSM

The design of an Inner-Rotor Large-Airgap Permanent Magnet Synchronous Machine (IRLA-PMSM) is presented in this paper, whose distinctive feature consists of integrating a thick carbon-fibre cylindrical layer that acts as both a sleeve and a flywheel. This results in large airgap and makes simplified mechanical modelling generally used for sleeve design no more suitable. Therefore, an advanced mechanical modelling is presented in the paper, which is combined with an electromagnetic and energy modelling in order to make the analytical design procedure compliant with all the design targets and constraints. The proposed IRLA-PMSM is validated through finite element analyses, which regard both mechanical and electromagnetic aspects at different operating conditions.