Multi-physics analysis of a high torque density motor for electric racing cars

This paper presents a newly developed high torque density motor design for electric racing cars. An interior permanent magnet motor with a flux-concentration configuration is proposed. The 18slots/16poles motor has pre-formed tooth wound coils, rare-earth magnets type material, whilst employing a highly efficient cooling system with forced oil convection through the slot and forced air convection in the airgap. Losses are minimized either by using special materials, i.e. non-oriented thin gage, laminated steel or special construction, i.e. magnet segmentation or twisted wires. The thermal behavior of the motor is modelled and tested using Le Mans racing typical driving cycle. Several prototypes have been built and tested to validate the proposed configuration.