Design aspects on magnet placement in permanent-magnet assisted synchronous reluctance machines

The design of permanent-magnet assisted synchronous reluctance machines (PMRSMs) for optimum 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. It describes the influence of insulation ratio, magnet size and magnet placement on the performance of the machine using finite element (FEM) based simulations. The results are compared based on developed torque, torque ripple and relative values of the resulting magnet and reluctance torque.