Electric motors play an important role in the electric vehicle (EV) and traction applications besides power electronic circuits and their control. Research on hybrid electric motors has increased in the last few years mainly aiming for sustainability. In this regard, the permanent magnet synchronous motor (PMSM), especially the interior permanent magnet motors using rare-earth permanent magnets, looked an ideal candidate for many EV and hybrid EVs (HEVs) because they offer both high torque density and high efficiency. However, the high price and availability of rare-earth permanent magnets has become a matter of concern in automotive application. This compelled the researchers to look into alternative machine designs and topologies, especially the development of hybrid machines that are not or less reliant on rare-earth metals.
The Synchronous Reluctance Motor (SynRM) is one such promising option for achieving high torque density and efficiency with low or no rare-earth PMs. In this talk, a new analytical method to design and analyse SynRM motor performance will be covered. This is followed by design aspects of SynRM that are optimized using Genetic Algorithm (GA) to achieve minimum torque ripple and maximum torque output. In addition, design of ferrite magnet based permanent magnet assisted SynRM (PMaSynRM) as an improvement over the SynRM will also be covered. Further, the performance of SynRM and PMaSynRM mainly suitable for traction application is investigated considering Toyota Prius 2004 IPM as benchmark motor in terms of electromagnetic performance, weight and material cost. A multi-objective genetic algorithm is adopted to find the trade-off design points. Finally, the results are compared and shall be discussed in the talk.