Design of LS-SynRM Rotor for Efficiency Improvement and Torque Ripple Reduction

The motor is one of the most power-consuming electrical devices worldwide. Therefore, improving the efficiency of motors is a crucial factor in reducing power consumption and carbon emissions. The international standard IEC 60034–30 classifies the efficiency grades of motors and promotes efficiency improvement through regulations. Current research is underway to upgrade efficiency grades from IE3 to IE4. The induction motor, which is the most widely used industrial motor, has the drawback of inevitable eddy current flow in the rotor due to its operating principle, resulting in associated losses. On the other hand, LS-SynRM, based on the same principle, simplifies motor control during startup and incurs eddy current losses only during operation initiation, leading to improved efficiency. This paper focuses on the optimal design of the rotor to achieve efficiency grades of IE4 or higher for industrial LS-SynRM while minimizing torque ripple.