Influence of Optimisation Target Functions on Synchronous Reluctance Machines Design

Synchronous reluctance machines (SynRel) are becoming very attractive for different applications because of their reluctance nature, easy manufacturability and low cost. Their design still represents a challange because of the many degrees of freedom that their rotor structure presents. Furthermore, in order to obtain a design with defined electromagnetic characteristics and low torque ripple machine geometry is needed to be optimised. In this paper, three different optimisations are performed on 6 poles SynRel motor with three flux barriers per pole. The aim of the work is to show the effect of the objective selection on the optimization process. An automatic procedure has been applied coupling finite element analysis with an optimization algorithm that is working towards the competitive targets of maximazing the torque, while minimizing the torque ripple and losses. The effects of these objectives on the geometrical variables are investigated in detail. The outcome of the analysis show how the problem definition heavily affects the obtained results. This gives useful insights on how to approach SynRel rotor design.