Analysis and Suppression of Synchronous Reluctance Motors with Mirror Asymmetric Rotors

Synchronous reluctance machines (SynRMs) have become a candidate alternative to permanent magnet synchronous machines (PMSMs) due to their characteristics of no rare earth and high torque density. However, the noise of the SynRMs remains a major concern that is gaining more and more attention. This paper aims to investigate the feasibility of the noise suppression of the SynRM with mirror asymmetric rotors. Initially, the topology of mirror asymmetric rotors is introduced. Then, the radial electromagnetic force densities are calculated based on the Maxwell tensor method, and the radial force harmonic of the 36-th frequency corresponding to the maximum noise point is optimized and reduced. Finally, the optimal SynRMs respectively with asymmetric, and mirror asymmetric rotors are analyzed. It is concluded that the mirror asymmetric SynRM has a significant prospect of noise suppression.