High-specific-power electric machines for electrified transportation applications-technology options

Specific power of an electric machine is defined as the ratio of output power to total weight. High-specific-power (HSP) electric machines are in high demand in electrified transportation systems such as more electric aircraft (MEA) and electric vehicles (EV), because they help reduce the fuel consumption and extend the traveling range. However, electromagnetic, thermal, mechanical and manufacturing issues put limits on the machines' specific power and represent major technological challenges in their design and fabrication. This paper provides a survey of actual HSP machines and discusses design considerations and technology options for HSP machine development. An HSP permanent magnet synchronous machine architecture is proposed based on the survey and discussions.