High-Speed Electrical Machines: Technologies, Trends, and Developments

This paper reviews the current technologies used in high-speed electrical machines through an extensive survey of different topologies developed and built in the industry and academia for several applications. Developments in materials and components, including electrical steels and copper alloys, are discussed, and their impact on the machines' operating physical boundaries is investigated. The main application areas pulling the development of high-speed machines are also reviewed to better understand the typical performance requirements.

I. Introduction

High-Speed rotating mechanical machinery has been developed and used for a long time, and it is now considered a mature and reliable technology for a number of engineering applications. Such applications include turbochargers, mechanical turbo-compounding systems, aeroengine spools, helicopter engines, racing engines, and fuel pumps with typical operational speeds in excess of 10 000 r/min and in excess of [1].