Design of an IE5 5.5kW Synchronous Reluctance Machine with Low Torque Ripple

This paper presents a set of design process of 5.5kW synchronous reluctance machine (SynRM) with high efficiency and low torque ripple. In the design procedure, the finite element analysis (FEA)-based differential evolution (DE) algorithm is introduced for machine geometry optimization. In addition, mirror adjacent poles with asymmetrical flux barriers are adopted to reduce machine torque ripple, the flux barrier end angles on both sides are different while the adjacent pole is mirror symmetrical with the q-axis. Moreover, slot skewing is applied to further reduce the torque ripple. At last, the rotor mechanical stress has also been checked. The results show that the efficiency of the machine has arrived 93.71%, the average torque is 36.23Nm with the torque ripple of less than 4%.