Design and performance analysis of a permanent-magnet assisted synchronous reluctance machine for an integrated charger application

In a plug-in hybrid electric vehicle equipped with an integrated charger, the electric machine and the inverter, which in traction mode are used to propel the vehicle and recover energy during braking, are also used to charge the battery from the grid while the vehicle is at rest. This paper studies the design and performance of a permanent-magnet assisted synchronous reluctance machine (PMaSynRM) both in traction and charging mode. Designing a PMaSynRM in order to obtain optimal reluctance and magnetic torque components is a complex task since rotor dimensioning for one torque component (magnet or reluctance torque) limits the possibility to optimize the other torque component. This paper identifies and relates the design parameters that influence these torque components and the performance of the machine using simulations based on the finite element method. The results are compared based on developed torque, torque ripple and relative values of the resulting magnet and reluctance torque.