Investigation of Different Pole Configurations in New Asymmetric Permanent Magnet Synchronous Reluctance Machines

Abstract

This paper investigates the impact of pole number and configuration on key performance characteristics of a new family of asymmetric permanent magnet synchronous reluctance machines (PMSynRMs). New variants of asymmetric PMSynRMs are presented here which integrate distinct interior PM (IPM) poles and reluctance poles into a single lamination. The torque enhancement principle relies on segregating the net torque into components generated by each pole type. Torque enhancement is achieved by optimally shifting the IPM poles relative to the reluctance poles, aligning the torque peaks generated by each pole type. A comprehensive comparative analysis is conducted between the proposed asymmetric and conventional topologies, with identical PM volume, copper loss, frequency, and frame size. The analysis evaluates torque production capability, unbalanced magnetic forces, torque ripple, losses, and power factor. The results reveal that the asymmetric PMSynRMs offer improved torque, power factor, and reduced torque ripple compared to conventional designs for pole numbers 4, 6, 8, and 10. However, some asymmetric designs exhibit the drawback of unbalanced magnetic forces, which should be taken into consideration. Finally, an asymmetric PMSynRM is prototyped and tested to verify the simulation results.