On the Design and Construction Assessments of a Permanent-Magnet-Assisted Synchronous Reluctance Motor

By appropriately inserting ferrite magnets into the rotor of a synchronous reluctance motor (SynRM), the machine operational power factors and torque outputs can be improved. With specific rotor structures to accommodate those ferrites, many of these permanent-magnet-assisted SynRMs (PMA-SynRMs) have been proposed to comply the expected operational objectives. For construction convenience, the ferrites that being inserted into the flux barriers of these PMA-SynRMs are generally in rectangular shapes; hence, some adjustments on the rotor flux barriers and additional bridges are required. Such changes will inevitably affect the performance of the original SynRMs with optimized rotor structures, and these tradeoffs are thus to be recovered by parts of those adopted ferrites. This paper will provide an evaluation index that can characterize the performance of PMA-SynRMs with different volume compositions of the ferrites, along with the impact assessments of the SynRMs with modified flux barriers such that those ferrites can be properly allocated. Based on the designs obtained from thorough 3-D finite-element analyses, a 3-hp PMA-SynRM will be constructed and the related experimental measurements will also be supported to validate the design adequacies.