Comparative Analysis of Permanent Magnet Assisted Synchronous Reluctance Motor with External-Rotor

In this paper an effective procedure is employed to assess a set of parameters which have major effect on the rotor design of a permanent magnet assisted synchronous reluctance motor (PMaSynRM) with external-rotor and consequently to deal with the geometrically complicated nature of the rotor. Inserting permanent magnets bricks into the flux barriers has several merits which include saturating the iron ribs in the rotor structure, improvement the torque producing capability and higher power factor. Furthermore, magnetizing inductances along d- and q-axes are significantly important to develop high average torque with low torque pulsation concurrently. Hence, sensitivity analysis of the geometric key parameters of an external-rotor PMaSynRM is carried out. To validate the electromagnetic performance characteristics of the machine different finite element method (FEM) analyses are performed. The analyses results approve the validity of the torque and power factor relations for the studied PMaSynRM. According to the results the electromagnetic torque of the PMaSynRM is increased compared to the pure SynRM because of the added permanent magnet torque.