Design Method and Performance Evaluation of Modular Multiphase PMSM with Hybrid Single/Double Layer Fractional-Slot Concentrated Winding

This paper proposes a general design method of modular multiphase permanent-magnet synchronous machine with hybrid single/double layer (HL) fractional-slot concentrated winding (FSCW), which indicates that double-layer (DL) FSCW machines satisfying two preconditions can be transformed into HL FSCW machines. HL FSCW machines with different slot and pole number combination are designed to prove the feasibility and universality of the proposed method. Performance of single-layer (SL) FSCW machine, DL FSCW machine, and HL FSCW machine are compared, from aspects of magnetomotive force, back electromotive force, average torque, torque ripple, core loss, eddy current loss in PMs (PM loss), efficiency, cogging torque, and flux density distribution. Besides, phase-to-phase magnetic isolation of HL FSCW machine, indicating by flux lines distributions and phase-to-phase mutual inductances, is also researched. HL FSCW machine has advantages of higher torque, lower PM loss, higher efficiency, better phase-to-phase thermal, physical and magnetic isolation compared with SL FSCW machine and DL FSCW machine.