Effect of Magnet Types on Performance of High-Speed Spoke Interior-Permanent-Magnet Machines Designed for Traction Applications

Three-Dimensional Modelling of Demagnetization and Utilization of Poorer Magnet Materials for EV/HEV Applications

“…Due to their high remanent flux density, Br, and high Hcj, the rare earth magnets, such as Neodymium Iron Boron (NdFeB), are excellent candidates that may contribute to high power density applications, while experiencing a minimal risk of demagnetization. However, due to the high and rather volatile price of the rare earth elements during the last decade, research toward using cheaper grade of magnets, such as NdFeB with less Dysprosium (Dy) contents, or ferrite magnets has, recently, become popular, [8], [9]. One of the major challenges with these designs is to mitigate the risk of demagnetization by appropriate modelling and optimization of the magnetic circuit path, which may be achieved by approaches such as: a) using interior permanent magnet topologies (IPM), b) providing leakage path for the demagnetization flux, by tapering the flux barriers toward the airgap [10], or allocating non-magnetic void on top [11] or both top and bottom [12] of the magnets, c) thickening the magnets width in the direction of magnetization, [9], [12], and d) increasing the number of poles [12].…”

Design of a brushless PM starter-generator for low-cost manufacture and a high-aspect-ratio mechanical space envelope

“…The 'design for cost' and 'design for manufacture' paradigms have gained increasing interest, which is reflected in the available literature [1]- [12]. In particular, research into machine designs with reduced quantities of rare-earth PM materials achieved through the adoption of interior PM machine topologies or the use of alternative PM materials such as ferrites, Dysprosiumfree or Dysprosium-less NdFeB.…”

Optimized design of a high-power-density PM-assisted synchronous reluctance machine with ferrite magnets for electric vehicles

“…Many kinds of PMSMs for traction application are actively studied [3][4][5]. PMSM, which use rare-earth PMs have some advantages, such as high torque density, high power density, a high power factor, a wide constant power speed range, and high efficiency, etc.…”