Effect of machine design on performance of reluctance synchronous machine

Low torque ripple in electrical machines is generally required to reduce acoustic noise and mechanical resonance vibration. To design for low torque ripple, however, affects the average torque and the power rating of the machine. In this paper the effect of stator winding chording and rotor skewing on the average torque and torque ripple of the normal laminated, internal flux barrier rotor reluctance synchronous machine is investigated. The 2-D finite element time-step method together with the basic machine equations are used in the analysis. It is shown that to design in general for low torque ripple and minimal effect on power rating of the reluctance synchronous machine, full-pitch stator windings must be used and the rotor must be skewed by a stator slot pitch. A low number of stator slots must be avoided.