Study on the Optimal Design of PMa-SynRM Loading Ratio for Achievement of Ultrapremium Efficiency

Globally, the efficiency of industrial motors is regulated through minimum energy performance standards (MEPS) to reduce energy consumption and CO₂ emission. Induction motor, used as a representative industrial motor, has a limit to efficiency improvement as the result of the additional copper loss of the rotor. To replace the induction motor, design of synchronous reluctance motor (SynRM) and permanent magnet assisted synchronous reluctance motor (PMa-SynRM), and the application of a small amount of permanent magnet, is actively studied in the industry. However, it is necessary to develop an ultrapremium efficiency motor beyond the superpremium efficiency to fulfill MEPS, which will be strengthened in the future. Therefore, this paper presents the optimal design method of SynRM by using the finite element method and response surface method to achieve superpremium efficiency. Furthermore, the redefinition of the loading ratio with shape parameters, and the design method of PMa-SynRM, using the loading ratio, is proposed to meet the ultrapremium efficiency. It is an effective design method that can shorten the time and process when designing ultrapremium efficiency PMa-SynRM from the existing SynRM, which is already mass-produced.