ReFreeDrive - Deliverable 3.2: CR-IM Electromagnetic Design Report for Inner and Outer Rotor Motor

The present report covers the electro-magnetic design analysis for Copper-Rotor Induction Motors (CR-IM) for inner and outer rotor for traction systems in Electric Drive Technologies (EDT). This is one of the technical solutions investigated by ReFreeDrive project. In Work Package 3, Inner Rotor (IR) and Outer Rotor (OR) induction motors configurations with cage built using die-casted or fabricated rotor technologies are proposed. When IR topology is used in combination with high rotational speed, i.e. ≥ 20000rpm, the torque density and the specific power are increased. Similarly, an OR topology can be used at lower rotational speed, i.e. ≤ 18000rpm, the increase in torque density and specific power is guaranteed due to the inherent higher diameter in the motor airgap. From a mechanical point of view, the mechanical analysis confirmed that the proposed IR and OR designs are within the maximum acceptable limits for the mechanical stress and natural frequencies that may occur. The outcome of this report provides clear guidelines on the CR-IM solutions for EDTs and identifies the optimum candidates design solutions for IR and OR topologies