Multilayer-Winding Versus Switched-Flux Permanent-Magnet AC Machines for Gearless Applications in Clean-Energy Systems

A variety of clean-energy systems, such as electric and hybrid vehicles or wind-power sources, can appreciably benefit from motors or generators directly connected to the mechanical part of the system. This paper describes the development and experimental investigation of two radically different low-speed permanent-magnet ac machines: a multilayer-winding synchronous machine and a switched-flux machine. The study allows an in-depth comparison of these divergent concepts from the viewpoint of practical applications in the clean-energy infrastructure.