Recent status on IPM traction drives for plug-in and hybrid electric vehicles

The past fifteen years have been an exciting period with tremendous advances in the development of interior permanent magnet (IPM) electrical machines. Over the course of this period, interior permanent magnet synchronous machines (IPMSM) have expanded their presence in specialized niche automotive markets for energy-efficient electric traction drives for the latest generation of hybrid-electric vehicles (HEV). Power ratings of available IPM motors and self-charging and/or plug-in IPM generators have dramatically increased by approximately few orders of magnitude during this period. Closer examination reveals that several different knowledge-based technological advancements and market forces have combined, sometimes in fortuitous ways, to accelerate the development of the impressive IPMSM drives technology. The purpose of this paper is to provide a broad explanation of the various factors that lead to the current state-of-the-art IPM technology, and to illustrate its application success in the automotive industry and railway.