Mechanical Design of a High-Speed Permanent Magnet Assisted Electrically Excited Synchronous Machine as Traction Motor

Abstract

This paper presents a novel mechanical design and mechanical design processes of an electrically excited synchronous machine with additional magnets. As hybrid excited synchronous machine, this machine is designed for electric vehicle as a traction motor. The maximum speed limits of electrically excited synchronous machine with and without magnets are generally discussed. With the new design, a permanent magnet assisted electrically excited synchronous machine with speeds up to 13500 1/min, and an electrically excited synchronous machine up to 15000 1/min are realized to fulfil the requirement of a high-speed traction motor. The maximum speed of the design is validated by performing an over-speed test at maximum operating temperature using a prototype rotor.