High Performance Air-Gap Winding Permanent Magnet Motors. Phase 1 Report

摘要

The object of the Phase I research project was to determine the feasibility of using air-gap armature windings to improve the overall performance of permanent magnet motors using rare-earth magnets, and in particular to increase the torque capacity of such motors. The research included a field analysis to determine the characteristic parameters of motors with permanent magnet fields and air-gap armature windings, and a thermal analysis to determine the limiting current density and to identify approaches to achieving high current densities. Four types of motors were investigated, all consisting of a stationary armature and permanent magnet rotor using samarium cobalt magnets: a conventional configuration, an air-gap winding, a helical air-gap winding, and a double rotor concept. All of the designs were considered to be air cooled; however, liquid cooling was also investigated.