Contact-less electromagnetic recharging system for heavy-duty bus flywheel storage

The paper presents a new configuration of axial flux magnetic gear (AMG) for the contact-less energy transfer to an on-board flywheel energy storage system (FESS) to supply heavy-duty electric buses. After defining the main FESS ratings, the AMG electromagnetic design is preliminarily assessed by analytical formulations and then verified by finite element analyses (FEAs) based on simplified models. Further FEAs are then carried out to improve the torque performance and to evaluate the electromagnetic efficiency during a typical recharge operation, comparing different ferromagnetic materials.