Design, Analysis and Experimental Evaluation of a Novel High-Speed High-Power Ferrite IPM Machine for Traction Applications

The paper presents the design and experimental evaluation of a novel (12000rpm, 80kW) Ferrite IPM machine for traction applications. First, the Ferrite IPM machine concept employing both circumferential and axial permanent magnets for airgap flux density improvement is introduced. An extensive sizing exercise to maximize the axial magnet contribution and meet the required torque-speed characteristic within the specified space envelope is undertaken, which led to the selection of a multi-stack rotor concept. In order to avoid the computationally intensive 3D FEA, an equivalent 2D FEA model is developed and employed for the design optimization of the traction machine. A full-size prototype Ferrite IPM traction machine is developed and tested, and it is shown that a maximum efficiency of 97% can be achieved.