Design and Analysis of a Fractional-Slot Concentrated-Wound PM-Assisted Reluctance Motor

Sammanfattning: The aim of this master thesis is to design and analyse a FSCW PMaSynRM (Permanent Magnet assisted Synchronous Reluctance Motor) for industrial applications. The design process includes analytical calculations (initial design and PM amount minimization) and nite element method (FEM) based design optimization. An overcompensated design is proved to be advantageous for a 10-pole reluctance motor. A comparative analysis with other rotor topologies was made, where motor performance, temperature e ects and production costs are taken into account. Detailed curves which describe eciency, power factor and current with respect to ambient temperature are studied for the proposed motor designs at di erent working points. The demagnetization risk is also taken into account and the safe working temperature ranges have been dened for all the considered motors. The results show that the initial motor design with 10 poles/12 slots PMaSynRM with NdFeB magnets has poor performance in terms of eciency and power factor, with huge amount of PM inserted. This is mainly due to the lack of reluctance torque for this relatively higher number of poles solution. Moreover, it has been found in literature and conrmed in this investigation that this negative e ect for the 10-pole motor is amplied due to the presence of the concentrated winding. Indeed, it is shown by simulations that the motor performance is improved by employing 8 poles/12 slots PMaSynRM conguration with a relatively lower NdFeB magnet amount, thanks to the improved rotor anisotropy. The 10 poles/12 slots interior permanent magnet (IPM) and surface mounted permanent magnet (SMPM) topologies present higher performance due to the e ective utilization of PM, mainly or completely producing the torque. Hence, IPM and SMPM do not su er the lack of anisotropy.