This paper proposes a design and optimization of ferrite assisted synchronous reluctance machine. SRM(Synchronous Reluctance Motor) could be applied in electrical vehicle traction due to its salient advantage. SRM is cheaper than traditional PMSM(Permanent Magnet Synchronous Motor) because it needs no permanent magnet or some ferrite(in Permanent Magnet Assisted Synchronous Machine), which means it has lower cost. Moreover, benefiting from the simple structure of rotor, SRM can be easily manufactured and has better robustness. Also, SRM has good performance in high efficiency and wide speed range. However, SRM has some shorts in average torque, torque ripple and Power Factor, so it is necessary to optimize the topology and improve its performance.
Compared with traditional Induction Machine and Permanent Magnetic Synchronous Machine, the structure of PMASRM(Permanent Magnet Assisted Synchronous Reluctance Motor) has good performance in EVs traction. But its disadvantage is apparent in torque ripple and torque density. It should be essential to optimize its pole/slot ratio and structure of rotor. This paper is going to compare two different kinds of topologies and optimize the structure to obtain better operating performance. The two topologies differ mainly in the types of flux barrier, one of type is angular and the other is curve. The optimization is about to be imposed in the structures considering multiple factors in order to compare the performance on the different topologies.
Two different structures of the rotor are shown in the following figure. The first one is angular flux barrier, the other one is curve flux barrier.