Design of a High-Speed Electric Propulsion System for Electric Vehicles

A novel high-speed electric propulsion system for automotive applications is presented in this paper. It consists of a high-speed ferrite-based permanent magnet synchronous machine with a wide constant-power speed range, which is coupled to the vehicle wheels through a double-stage magnetic gear transmission system. Both the electrical machine and the magnetic gear have been designed based on advanced mechanical and electromagnetic modelling in order to comply with all design targets and constraints. The proposed solution has been evaluated by means of a simulation study, which is performed in MATLAB-Simulink. Particularly, a performance assessment has been carried out by referring to different driving cycles and case studies, namely a conventional low-speed electric propulsion system equipped with a mechanical single-gear transmission system and the proposed high-speed electric propulsion system driven by two different control strategies for comparison purposes.