Design and performance of 6-slot 5-pole PMFSM with hybrid excitation for hybrid electric vehicle applications

An interest in electric vehicles (EVs) and hybrid electric vehicles (HEVs) from automakers, governments and customers due to concerns on our environment makes it as more attractive research. Since electric motors are the core of both EVs and HEVs, it is a pressing need for researchers to develop advanced electric motors. As one of the candidates, permanent magnet flux switching machine (PMFSM) with additional coil excitation has several attractive features compared to conventional interior permanent magnet synchronous machines (IPMSM) used in HEV. This is because of its variable flux control capability and robust rotor structure that makes it possible to apply for high speed motor drive system with reduction gear. This paper presents an investigation into design possibility of 6-slot 5-pole PMFSM with hybrid excitation for traction drives in HEVs. An improved design is examined in effort to gain a better performance in its maximum torque and power production. As the design results, the designed motor enables to keep the same power density in existing IPMSM installed on a commercial SUV-HEV.