Torque ripple reduction of synchronous reluctance machine by using asymmetrical barriers and hybrid magnetic core

As there is no need of permanent magnet (PM) material and only silicon steel sheet required on the rotor, synchronous reluctance machine (SynRM) can be used for many applications and draws a great research interest. For the SynRM, the torque ripple is a big issue and a great of work could been done on reducing it. In this paper, asymmetrical magnetic flux barriers in the SynRM rotor were studied comprehensively, including angle and width of each layer and each side of the magnetic barrier. The SynRMb with asymmetrical and parallel magnetic flux barrier was found as the best way to design SynRM based on the multi-objective design optimization method. Moreover, each parameter was studied to show the design rule of the asymmetrical magnetic flux barrier. As the average torque will be reduced with the asymmetrical barrier is used, the grain-oriented silicon steel is used on stator teeth of the SynRMb (SynRMbG) was proposed and studied. The analysis results show that the proposed new method can make the SynRM have better performance.