Comparison of high-speed PM machine topologies for electrically-assisted turbocharger applications

This paper presents a performance comparison between different high-speed (HS) permanent-magnet (PM) topologies for electrically assisted turbocharger (EAT) applications. The focus of the research is mainly on the efficiency and torque capability comparison of three surface-mounted PM machines: a slotless toroidally wound, and two 6-slot machines having different slot shapes. The base specification of the application is 15 kW @ 150 krpm. Mechanical considerations and general guidelines are also given in the paper to ensure a realistic design of the motor regarding the application. This paper shows that while one topology offers the highest efficiency but a poor torque density, the other two give a better compromise.