Optimisation of a High Speed Copper Rotor Induction Motor for a Traction Application

This paper deals with the optimisation of a 200kW, 20krpm machine for an electric vehicle application using Motor-CAD and optiSLang software. The main goal of the research is to design a low cost, rare-earth free magnet motor while ensuring mass production feasibility and providing higher performance than current available technologies. The induction motor with copper rotor cage, either die-casted or fabricated, is selected as a potential candidate. The stator winding is of hairpin type and both rotor and stator parts benefit from direct cooling. The machine is optimised electromagnetically and thermally to meet the peak and continuous performance requirements with respect to the project specifications. In particular, the efficiency computation over the typical WLTP3 drive cycle is considered in the optimisation process. The latter is looked into details and uses a meta-model based approach which allows to evaluate thousands of design topologies in a computationally efficient way for a given optimisation scenario.