Performance of automotive permanent magnet machines with different sizes, rare-earth magnets and winding configurations

Even though the price of rare-earth magnets has become a serious concern, interior permanent magnet (PM) machines are gaining increasing attention among researchers due to their high torque density and good field weakening performance. Therefore, researchers have attempted to reduce the use of magnet materials but at the same time still maintain the output performance of the interior PM machine. This paper compares the performance of smaller PM machines in order to reduce the usage of magnet material by using finite element analysis (FEA). This paper also considers the temperature of proposed PM machines because smaller machines may suffer from problem with higher temperature due to higher loss density and thus it is important to make sure that the machines can run safely. Apart from that, the characteristics of PM machines equipped with distributed and concentrated winding for automotive applications are considered. An 8-pole 48-slot model and an 8-pole 12-slot model are designed in constrained sizes. Finally, the appropriate motor winding is proposed.