Saliency-Enhanced Spoke-Type Rotor Geometry for Permanent Magnet Volume Reduction in Hybrid and Electric Vehicle Motors

摘要

Today's Hybrid and Electric Vehicles (HEV) market share is growing fast and the main car manufacturers are planning substantial investments to develop performant, reliable and affordable electric powertrains. Industry and research agree considering Interior Permanent Magnet (IPM) motors to be one of the most suitable technologies for automotive traction applications. However, these motors typically make use of expensive rare-earth permanent magnets and, as the emerging economies will increase the demand for these materials, prices will rise further making rare-earth-based solutions less competitive. Researchers have proposed different solutions: synchronous reluctance motors, replace rare-earth PM with ferrite, but probably the most immediate option is the design optimization to reduce the PM mass. In this paper a saliency enhanced spoke-type rotor geometry is proposed in order to replace the 2010 Toyota Prius rotor with a 28% reduction in the PM mass. This approach is studied with a novel analytic model and extensive Finite Element simulations.