Automotive Electric Motors, Generators, and Actuator Drive Systems With Reduced or No Permanent Magnets and Innovative Design Concepts

Due to environmental and energy concerns, electric vehicles (EVs) and hybrid EVs (HEVs) are gaining increased attention. At the heart of the drive system of these vehicles is the electric machine and drive. For these applications, high power density, high torque density, wide speed range, and efficiency are of primary importance. To meet these demands, interior-permanent-magnet (IPM) machines have been widely used. However, IPM machines use rare-earth PMs (usually neodymium-iron-boron magnets) in their structure. The price of these types of rare-earth PMs has increased by orders of magnitude over several years. Due to the high cost and limited supply of this material, the use of IPM machines in HEV applications is now being challenged. In fact, many researchers are working on other machines that can compete with IPM machines in terms of size, efficiency, power, and torque density. With consideration of the above points, there is a timeliness to this important topic; thus, we are pleased to present this "Special Section on Automotive Electric Motors, Generators, and Actuator Drive Systems With Reduced or No Permanent Magnets and Innovative Design Concepts" of the IEEE Transactions on Industrial Electronics that consists of 12 papers reporting on the most recent research on automotive electric drive machines. Most of these papers focus on machines with less or no rare-earth PM material in their structure, although control is also important, and there are some papers related to this topic.