Design of a High-Speed Ferrite-Based Brushless DC Machine for Electric Vehicles

In this paper an analytical procedure for the preliminary design of a high-speed ferrite-based brushless dc machine (HS-BLDC) has been proposed. In particular, mechanical and electromagnetic modeling have been developed in order to take into account their mutual influence in the definition of the geometry of the electrical machine. In addition, suitable design targets have been imposed in accordance with electric vehicle application requirements. Hence, several mechanical and electromagnetic constraints have been introduced in order to comply with high-speed operation, preventing demagnetization issues of ferrite magnets as well. Subsequently, an HS-BLDC characterized by an inner rotor configuration has been designed in accordance with the proposed methodology. The analytical procedure and the corresponding results have been reported and validated by means of finite element analyses, highlighting the effectiveness of the proposed configuration and design solutions.