Influence of Mixed Stator Winding Configurations and Number of Rotor Flux-Barriers on Torque and Torque Ripple of Five-Phase Synchronous Reluctance Motors

The five-phase synchronous reluctance motor is a strong contender in applications that require fault tolerance, as the motor can still run with loss of one or two stator phase (s). This paper presents the effect of mixed stator winding configurations and number of rotor flux-barriers on average torque and torque ripple of five-phase transverse-laminated synchronous reluctance motors (SynRMs). The five-phase stator windings are designed as four poles and distributed in 40 slots. Three different winding configurations having the same number of series conductors per phase are designed and modelled together with rotors having two, three and four rotor flux-barriers per pole. The different stator windings consist of the conventional double layer (CDL or DL), triple layer (TL) and the combination of double and triple layer (DTL) configurations. In total nine SynRMs have been designed and modelled using the 2D Finite Element Method (FEM). The Finite Element Analysis (FEA) results evidenced that the five-phase SynRM designed with mixed DTL stator winding configuration and three rotor flux barriers per pole have produced high average torque with low torque ripple content. The FEA results also showed that the SynRM designed with TL stator winding configuration and four rotor flux barriers per pole dropped tremendously the torque ripple, but it also dropped the average toque.