Impacts of interior permanent magnet machine technology for electric vehicles

The past twenty years have been an exciting period with tremendous advances in the development of interior permanent magnet (IPM) electrical machines. Over this period, the interior permanent magnet synchronous machines (IPMSM) have expanded their presence in the automotive marketplace of high-efficiency electric traction drives for the latest generation of electric vehicles (EV) and hybrid-electric vehicles (HEV). Closer examination reveals that several different knowledge-based technological advancements and market forces have combined to accelerate the development of the impressive IPM drives technology. The purpose of this paper is to provide a brief statement on impacts of the various factors that lead to the current state-of-the-art IPM motor technology, and to illustrate its application success in the automotive industry. Particularly, the impact of IPM machines on cost and reliability for EV and HEV applications is highlighted in the paper.